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I n t e r mo u n t a i n We s t Jo i n t Ve n t u r e 2 013 I m p l e m e n t a t i o n Pl a n Stre ngthe ning Scie nce a nd Pa r tne r ships


2 013 I m p l e m e n t a t i o n Pl a n S t r e n g t h e n i n g S c i e n c e a n d Pa r t n e r s h i p s

Intermountain West Joint Venture 1001 S. Higgins Avenue, Suite A1 Missoula, MT 59801 T. 406.549.0732 F. 406.549.0496 E. info@iwjv.org

www.iwjv.org Citation: Intermountain West Joint Venture. 2013 Implementation Plan – Strengthening Science and Partnerships. Intermountain West Joint Venture, Missoula, MT.

Cover Photos: Working Ranch Photo-John Ranlett; Rancher-Lori Reed; Sage-grouse-Ron Stewart; Northern Pintail-USFWS; Sandhill Crane-Utah Division of Wildlife Resources; Mule Deer-Mike Keller

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ACKNOWLEDGEMENTS This Plan represents an important benchmark for bird habitat conservation in the Intermountain West, made possible by the tireless efforts of individuals who care deeply about the remarkable landscapes and natural resources of this region. The crafters of this Plan believe that the best way to sustain bird populations at desired levels is to conserve habitat through a science-driven, partnership-based approach that considers the needs of wildlife and people. We are forever grateful to the folks that graciously contributed their time and energy to this Plan. The partnership is truly stronger than the sum of its parts. – Dave Smith, Intermountain West Joint Venture Coordinator, March 2013

The 2013 Intermountain West Joint Venture (IWJV) Implementation Plan was developed through extensive collaboration among some of the best avian ecologists and habitat conservationists in the Intermountain West, organized through the IWJV Science Teams for Waterfowl, Shorebirds, Waterbirds, and Landbirds. This Plan is a product of the IWJV Science Team members, Management Board and staff, and other Joint Venture partners who contributed to its development and presentation. All played crucial roles in bringing this project to fruition, but the principal authors listed below truly did the heavy lifting – and for those contributions we are extremely grateful.

Special Recognition Goes To: Principal Authors • Brad Andres, U.S. Fish and Wildlife Service • Daniel Casey, American Bird Conservancy

Plan Contributors IWJV Science Team Members Waterfowl Science Team

• Ashley Dayer, Strategic Communications Consultant

• Tom Aldrich, Utah Division of Wildlife Resources

• Patrick Donnelly, Intermountain West Joint Venture

• Brad Bales, Oregon Department of Fish and Wildlife

• Alison Duvall, Intermountain West Joint Venture

• Brad Bortner, U.S. Fish and Wildlife Service

• Gary Ivey, International Crane Foundation

• Bruce Dugger, Oregon State University

• Don Paul, AvianWest, Inc.

• Joseph Fleskes, U.S. Geological Survey

• Mark Petrie, Ducks Unlimited, Inc.

• Don Kraege, Washington Department of Fish and Wildlife

• Dave Smith, Intermountain West Joint Venture

• Craig Mortimore, Nevada Department of Wildlife

• Kelli Stone, Two Birds One Stone LLC

• Mike Rabe, Arizona Game & Fish Department

• Sue Thomas, U.S. Fish and Wildlife Service

• Dan Yparraguirre, California Department of Fish and Game

• Josh Vest, Intermountain West Joint Venture • Tara Zimmerman, Kinglet Consulting, Inc

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ACKNOWLEDGEMENTS Waterbird Science Team

Landbird Science Team (see note below)

• John Alexander, Klamath Bird Observatory

• John Alexander, Klamath Bird Observatory

• Suzanne Fellows, U.S. Fish and Wildlife Service

• Bob Altman, American Bird Conservancy

• Jenny Hoskins, U.S. Fish and Wildlife Service

• Geoff Geupel, PRBO Conservation Science

• Dave Mauser, U.S. Fish and Wildlife Service

• Michael Green, U.S. Fish and Wildlife Service

• Colleen Moulton, Idaho Department of Fish and Game

• David Hanni, Rocky Mountain Bird Observatory

• John Neill, Utah Division of Wildlife Resources

• Aaron Holmes, PRBO Conservation Science

• Andrea Orabona, Wyoming Game & Fish Department

• Larry Neel, Nevada Department of Wildlife

• Don Paul, AvianWest, Inc.

• Russ Norvell, Utah Division of Wildlife Resources

• Dave Shuford, PRBO Conservation Science

• Terry Rich, U.S. Fish and Wildlife Service

• Jennifer Wheeler, U.S. Fish and Wildlife Service

• Rex Sallabanks, Idaho Department of Fish and Game

Shorebird Science Team • Brad Andres, U.S. Fish and Wildlife Service • Daniel Casey, American Bird Conservancy • Wendell Gilgert, Natural Resources Conservation Service • Suzanne Fellows, U.S. Fish and Wildlife Service

• Jaime Stephens, Klamath Bird Observatory Note: The Landbird Strategy was developed through collaboration with the Partners in Flight - Western Working Group. We give special thanks to the working group members that provided valuable input to the Strategy.

• Gary Ivey, International Crane Foundation • Dave Mauser, U.S. Fish and Wildlife Service • Colleen Moulton, Idaho Department of Fish and Game • Larry Neel, Nevada Department of Wildlife • Don Paul, AvianWest, Inc. • Mark Petrie, Ducks Unlimited, Inc. • Bridget Olson, U.S. Fish and Wildlife Service • Dave Shuford, PRBO Conservation Science • Kelli Stone, Two Birds One Stone LLC • Sue Thomas, U.S. Fish and Wildlife Service

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ACKNOWLEDGEMENTS Other Contributions Graphic Design, Photos, Technical Assistance, and Management Board Leadership We extend our sincere appreciation to Sara Kauk, DesignMissoula, and Amy Farrell, times2studio, for formatting the Plan. We also recognize the individuals, organizations, and agencies that contributed photos: Daniel Casey, Colorado Division of Wildlife & Parks, Larry Kruckenberg, Jeremy Roberts of Conservation Media, Natural Resources Conservation Service, and U.S. Fish and Wildlife Service. We thank the following IWJV Staff members, contractors, or partners that contributed to the project: Barb Bresson, Susannah Casey, Geodata, Inc., Randall Gray, Katie Guenzler, Lori Reed, Terry Mansfield, Christopher Rustay, and former Waterbird Science Team Leader, Nanette Seto. We also thank the U.S. Fish and Wildlife Service for significant contributions from its Migratory Bird Management Program, Region 1, and the national North American Waterbird Conservation Plan Coordinator; these funds played an instrumental role in the shorebird and waterbird conservation planning.

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Further, we offer sincere thanks to the IWJV Management Board for leadership, direction, and guidance. Each and every member of the Management Board from 2007 to 2013 played an important role in this process, and we are eternally grateful for those contributions. We are especially indebted to the following Board Chairs for their leadership and savvy in the project: Alan Clark (20112013), Brad Bortner (2009-2011), and Larry Kruckenberg 2007-2009). Collectively, they brought many decades of experience to the development of this Plan. The staff of the IWJV offers sincere and heartfelt thanks for those contributions!

Contact Dave Smith Intermountain West Joint Venture Coordinator 1001 S. Higgins Avenue, Suite A1 Missoula, MT 59801 Dave_W_Smith@fws.gov 406.549.0287 (office) 406.370.7729 (cell) www.iwjv.org

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The mission of the Intermountain West Joint Venture is to conserve priority bird habitats through partnership-driven, science-based projects and programs. We bring people and organizations together to leverage technical and financial resources, building our collective capacity to achieve conservation at meaningful scales.

Photo by USF WS

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EXECUTIVE SUMMARY

Photo by Rio de la Vista

The 2013 Intermountain West Joint Venture (IWJV) Implementation Plan (Plan) – the third in the history of the Joint Venture – establishes a framework for sciencebased, habitat conservation that supports the work of a diverse and substantial network of conservation partners. The Plan will direct efforts of the Joint Venture over at least the next five years. The Plan is built upon the model of Strategic Habitat Conservation (SHC – i.e. the iterative cycle of biological planning, conservation design, habitat delivery, monitoring, evaluation, and research). For migratory birds, this involves translating continental bird population objectives to ecoregional scales and identifying the quantity and quality of habitat needed to support priority bird populations at goal levels. The geographic and taxonomic scope of the IWJV requires a much different approach than has been used with the implementation plans of other Joint Ventures. The Intermountain West is characterized by an extremely high level of habitat heterogeneity, which requires establishing a relatively small number of focal species and carrying out biological planning and conservation design in focal landscapes or ii.2

ecoregions. This precludes the IWJV from developing a synthetic Implementation Plan for all priority birds, JVwide, at the present time. Nevertheless, the Plan lays out a vision for addressing IWJV science needs in a systematic, step-wise, and transparent manner. This approach is demonstrated through the presentation of populationhabitat modeling completed to date for specific groups of birds in specific landscapes for four major bird groups – waterfowl, shorebirds, waterbirds, and landbirds. Biological planning and conservation design required to establish defensible habitat objectives has been underway for several years and is complete for certain groups of birds at certain times during their annual life cycle in certain portions of the Intermountain West. For example, the Plan comprehensively identifies habitat needed to support spring-migrating waterfowl at North American Waterfowl Management Plan goal levels in Southern Oregon and Northeastern California. Likewise, it includes the results of the most detailed conservation strategy ever developed for shorebirds at the Great Salt Lake, one of the most important stopover sites for shorebirds in the Western Hemisphere.

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EXECUTIVE SUMMARY Remaining data gaps clearly hinder our ability to develop habitat objectives or spatially explicit decisionsupport tools for many priority species. However, this Plan consolidates our current knowledge of certain priority avian species, species-habitat relationships, and the quantity and location of habitat needed to support populations of those birds at goal levels – beginning in landscapes with the greatest continental significance to shorebirds and waterfowl. It will be immediately valuable to habitat mangers in those landscapes and will provide a framework for future efforts to establish habitat objectives for other species or in other landscapes. The Plan includes a Habitat Conservation Strategy (Chapter 8) that defines the IWJV approach to habitat conservation delivery through establishment of habitat goals, objectives, and priorities. This chapter is included to reflect the emphasis and strength of the IWJV partnership in delivering on-the-ground habitat protection, restoration, and enhancement. Habitat conservation delivery has long been the hallmark of the IWJV partnership. Today, the Management Board allocates a significant amount of funding and staff resources to strengthening the habitat delivery capacity and effectiveness of a wide array of IWJV partners. We are actively engaged with partners in facilitating effective delivery of Farm Bill conservation programs; assisting state fish and wildlife agencies in habitat conservation through partnerships; working with the land-protection community to foster strategic habitat protection for priority avian habitats; and delivering a Capacity Grants Program intended to help IWJV partners capitalize on existing funding sources from public and private conservation programs.

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The Habitat Conservation Strategy provides an overview of the mechanisms available to the IWJV partnership for conservation delivery implementation – a key cog in the SHC wheel. This chapter describes, to the best of our ability at the present time what needs to be done to facilitate landscape-scale habitat conservation. As such, it provides a critical connection to the science platform established in the Waterfowl, Shorebird, Waterbird, and Landbird Chapters and provides an overview of some of the programmatic and funding mechanisms needed to influence avian habitats in key landscapes. Finally, the Plan includes a comprehensive Strategic Communications Plan to promote effective integration of biological planning, conservation design, on-theground habitat conservation, and monitoring, evaluation, and applied research among an incredibly diverse and extensive array of conservation partners. The Strategic Communications Plan will facilitate transfer of key findings of this Implementation Plan to the vast array of partners working to conserve avian habitats in the Intermountain West. This Plan represents a significant step in the evolution of the IWJV toward science-based, partnership-driven habitat conservation. Its defining characteristic isn’t the number of explicit decision-support tools it contains, but rather the foundation it provides for increasingly tightening the linkage between science and habitat conservation delivery. Foremost, it establishes a strategic framework for the future business of this diverse Joint Venture across the vast landscapes of the Intermountain West.

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Inside this Document

Ta b l e of Co n t e n t s

Chapter 1 Introduction........................................................................................................................... 1.2 Plan Overview.. ...................................................................................................................... 1.4 Foundation & Focus of the Plan............................................................................................ 1.5 Mission & Goals.. ................................................................................................................... 1.6 History................................................................................................................................... 1.7 •

1994-2005 Era.................................................................................................................. 1.7

2006-2013 Era.................................................................................................................. 1.7

Administrative Structure.. .................................................................................................... 1.10 Relationship to National Bird Plans & Initiatives................................................................. 1.11 •

North American Waterfowl Management Plan (NAWMP)................................................... 1.11

United States Shorebird Conservation Plan (USSCP)....................................................... 1.12

North American Waterbird Conservation Plan (NAWCP).. .................................................. 1.12

North American Landbird Conservation Plan.. .................................................................. 1.12

North American Bird Conservation Initiative (NABCI)........................................................ 1.13

Chapter 2 Introduction........................................................................................................................... 2.2 Ecological Setting................................................................................................................. 2.3 •

Northwestern Forested Mountains Ecological Region (162.2 million acres).. ........................ 2.3

North American Deserts Ecological Region (278.9 million acres).. ....................................... 2.4

Temperate Sierras Ecological Region (19.9 million acres)................................................... 2.7

Defining an Ecological Framework.. ...................................................................................... 2.9 •

Global/Intercontinental Scale (Level I Ecoregions).. ............................................................ 2.9

National/Sub-continental Scale (Level II Ecoregions).. ...................................................... 2.10

Regional Scale (Level III Ecoregions)............................................................................... 2.12

Local Scale (Level IV Ecoregions).................................................................................... 2.14

Conservation Estate & Landownership Patterns................................................................. 2.15 Literature Cited .................................................................................................................. 2.17

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Chapter 3 Introduction........................................................................................................................... 3.2

Ta b l e of Co n t e n t s

Biological Foundation Framework Overview ........................................................................ 3.4 Identify Priorities for Conservation Science.. ........................................................................ 3.5 •

A Strategic Framework for Conservation Science Priorities................................................ 3.5

Biological Planning . ........................................................................................................... 3.10 •

Assess Population Status.. .............................................................................................. 3.10

Determine Population Objectives.. ................................................................................... 3.10

Identifying Limiting Factors............................................................................................. 3.11

Estimating Net Landscape Change.................................................................................. 3.11

Conservation Design........................................................................................................... 3.13 •

Species-Habitat Models.................................................................................................. 3.13

Focus Areas................................................................................................................... 3.14

Characterize Past, Current and Potential Future Landscapes........................................... 3.14

Biological Capacity and Habitat Objectives..................................................................... 3.17

Decision Support Tools................................................................................................... 3.17

Monitoring & Evaluation...................................................................................................... 3.18 Assumption-driven Research ............................................................................................. 3.19 Initiating a Strategic Plan for Science Priorities ................................................................ 3.20 Literature Cited .................................................................................................................. 3.21

Chapter 4 Introduction........................................................................................................................... 4.2 Non-Breeding Waterfowl....................................................................................................... 4.4 •

Structure of Non-Breeding Waterfowl Plan.. ....................................................................... 4.4

Biological Planning........................................................................................................... 4.4

Conservation Design......................................................................................................... 4.6

Habitat Delivery................................................................................................................ 4.6

Southern Oregon & Northeastern California (SONEC).. ......................................................... 4.7 •

Biological Planning........................................................................................................... 4.7

Conservation Design....................................................................................................... 4.14

Habitat Objectives for SONEC: Spring............................................................................. 4.24

Great Salt Lake.................................................................................................................... 4.25 •

Biological Planning......................................................................................................... 4.25

Conservation Design....................................................................................................... 4.30

Columbia Basin.. .................................................................................................................. 4.37 •

Biological Planning......................................................................................................... 4.37

Conservation Design....................................................................................................... 4.42

Breeding Waterfowl............................................................................................................. 4.53 Literature Cited................................................................................................................... 4.55 Appendix A. Waterfowl Science Team Members.. ................................................................ 4.58

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Chapter 5

Ta b l e of Co n t e n t s

Introduction........................................................................................................................... 5.3 •

Guiding Documents.......................................................................................................... 5.3

Partnership Guidance....................................................................................................... 5.4

Planning Approach: Key-Site Strategy, Bioenergetics Modeling.. ........................................ 5.4

Description of the Region.. ................................................................................................ 5.4

An Introduction to Biological Planning for Shorebirds.......................................................... 5.5 Shorebirds of the Intermountain West.. ................................................................................. 5.6 Shorebird Habitat Types........................................................................................................ 5.9 Population Status & Trends................................................................................................. 5.11 Threats & Limiting Factors.................................................................................................. 5.13 •

Water Quantity and Quality.. ............................................................................................ 5.13

Habitat Loss or Degradation.. .......................................................................................... 5.13

Agriculture.. .................................................................................................................... 5.13

Rural Urbanization.......................................................................................................... 5.14

Invasive Species............................................................................................................. 5.14

Contaminants and Disease Outbreaks............................................................................. 5.15

Other Anthropogenic Factors.......................................................................................... 5.15

Climate Change.............................................................................................................. 5.15

Population Estimates & Objectives..................................................................................... 5.16 •

Population Estimates...................................................................................................... 5.16

Assumptions and Limitations of Data.. ............................................................................. 5.16

Regional Population Objectives....................................................................................... 5.16

Key Sites for Shorebird Conservation................................................................................. 5.19 •

The Great Salt Lake Key Site Conservation Strategy........................................................ 5.21

Blanca Wetlands Shorebird Habitat Strategy.. .................................................................. 5.22

Breeding Shorebird Focal Species...................................................................................... 5.22 •

Focal Species Profiles.. ................................................................................................... 5.23

Literature Cited................................................................................................................... 5.25 Appendix A. Shorebird Science Team Members.................................................................. 5.27 Appendix B. Status of Shorebird Species.. .......................................................................... 5.28 Appendix C. Common & Scientific Names of Shorebird Species Listed in this Document.. ..................................................................................................... 5.30

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Chapter 6 Introduction........................................................................................................................... 6.3

Ta b l e of Co n t e n t s

Waterbirds & The Intermountain West Region.. ..................................................................... 6.6 Overview of Planning Approach............................................................................................ 6.9 Waterbird Population Status & Trends.. ............................................................................... 6.10 •

Eared Grebe................................................................................................................... 6.12

Double-Crested Cormorant............................................................................................. 6.12

White-faced Ibis............................................................................................................. 6.13

Sandhill Cranes.............................................................................................................. 6.13

Caspian Tern.................................................................................................................. 6.15

Threats & Limiting Factors.................................................................................................. 6.16 •

Loss and Degradation of Wetland Habitat........................................................................ 6.16

Water Supply and Security.............................................................................................. 6.16

Water Quality.. ................................................................................................................ 6.18

Loss of Foraging Habitat................................................................................................. 6.18

Climate Change.............................................................................................................. 6.18

Population Estimates & Objectives..................................................................................... 6.20 Focal Species...................................................................................................................... 6.21 •

Focal Species Approach................................................................................................. 6.21

Focal Species and Conservation Planning....................................................................... 6.24

Focal Species Profiles.. ................................................................................................... 6.25

Population Inventory & Monitoring...................................................................................... 6.28 •

Western Colonial Waterbird Survey, 2009–2011............................................................... 6.28

North American Marsh Bird Monitoring............................................................................ 6.28

Continental Marsh Bird Monitoring Pilot Study.. ............................................................... 6.29

Periodic or Annual Waterbird Surveys.. ............................................................................ 6.29

Species-Specific Surveys.. .............................................................................................. 6.30

Next Steps........................................................................................................................... 6.32 Literature Cited................................................................................................................... 6.33 Appendix A. Waterbird Science Team Members.................................................................. 6.39 Appendix B. Double-Crested Cormorant Breeding Pairs in the Intermountain West.......... 6.40 Appendix C. Caspian Tern Breeding Pairs in the Intermountain West.. ............................... 6.41 Appendix D. White-faced Ibis Breeding Pairs in the Intermountain West........................... 6.43 Appendix E. Focal Area Profiles – Descriptions & Threats.................................................. 6.46 Appendix F. Literature Cited in Appendices........................................................................ 6.64

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Chapter 7 Introduction........................................................................................................................... 7.3

Ta b l e of Co n t e n t s

Definition of Biological Planning Units.. ................................................................................ 7.4 Species Prioritization............................................................................................................ 7.5 •

PIF Species Assessment Database and Continental Plan................................................... 7.5

PIF State Plans................................................................................................................. 7.5

Fish and Wildlife Service Birds of Management Concern (BMC).. ........................................ 7.6

State Wildlife Action Plans................................................................................................ 7.6

Habitat Prioritization & Characterization............................................................................ 7.10 •

IWJV Terrestrial Habitat Overview (Landscape Characterization).. ..................................... 7.10

Habitat Classification Scheme: Crosswalk of Vegetative Associations.............................. 7.11

Decision Support Tool: The HABPOPS Database.. ............................................................ 7.12

Bird Population (Step-down) Objectives............................................................................. 7.13 •

Step-down Objectives by BCR/State Polygons ............................................................... 7.13

Habitat-based (Bottom-up) Objective Setting & Targeting Landscapes.............................. 7.25 •

Sagebrush Objectives..................................................................................................... 7.25

Grassland Objectives...................................................................................................... 7.36

Priority Actions . ................................................................................................................. 7.43 •

Recommended Approaches for Conservation, by BCR/State............................................ 7.43

Literature Cited................................................................................................................... 7.54 Appendix A. Landbird Science Team Members................................................................... 7.55 Appendix B. Landbird Species of Continental Importance in the Intermountain West Avifaunal Biome . ................................................................................................................ 7.56 Appendix C. Total Acreage by IWJV Habitat Type by State and BCR.. ................................. 7.57 Appendix D. Crosswalk of Vegetative Associations by IWJV Cover Types......................................................................................................................... 7.64 Appendix E. Overlaps Between Mapped Ranges of IWJV Focal Species and BCR/State Polygons............................................................................................................ 7.74 Appendix F. Population Trends of Focal Landbird Species, IWJV States, 1967–2007.......... 7.76 Appendix G. Priority Actions for Additional Habitats and Focal Species in BCRs 9, 10 and 16.. .............................................................................................................. 7.77 Appendix H. BBS Trend Maps for IWJV Focal Landbird Species......................................... 7.83

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Chapter 8 Introduction........................................................................................................................... 8.2

Ta b l e of Co n t e n t s

Targeting Conservation......................................................................................................... 8.3 Wetland Habitat Conservation............................................................................................... 8.4 •

Priority Wetland Dependent Bird Species.. ......................................................................... 8.6

Key Threats to Wetlands................................................................................................... 8.6

Southern Oregon and Northeastern California (SONEC)................................................... 8.10

Great Salt Lake (GSL)..................................................................................................... 8.13

Status of Conservation Planning and Science for Wetland Focal Areas............................. 8.16

Funding Opportunities.................................................................................................... 8.16

Resources...................................................................................................................... 8.16

Sagebrush Habitat Conservation.. ....................................................................................... 8.17 •

Priority Sagebrush Bird Species...................................................................................... 8.18

Key Threats to Sagebrush Habitat................................................................................... 8.18

Funding Opportunities.................................................................................................... 8.24

Resources...................................................................................................................... 8.24

Grassland Habitat Conservation.. ........................................................................................ 8.25 •

Priority Grassland Bird Species....................................................................................... 8.25

Key Threats to Grasslands.............................................................................................. 8.25

Funding Opportunities.................................................................................................... 8.27

Resources...................................................................................................................... 8.27

Literature Cited................................................................................................................... 8.28

Chapter 9 Introduction........................................................................................................................... 9.2 Summary of the Communications Plan................................................................................. 9.3 Approach............................................................................................................................... 9.4 •

Background to Strategic Communications......................................................................... 9.4

Capacity Building & Engagement Approach....................................................................... 9.4

History & Past Accomplishments of IWJV Communications................................................. 9.5 Needs Assessment for Defining 5-Year Goals....................................................................... 9.6 Audience Assessments & Situational Analyses..................................................................... 9.8 Communications Campaigns.. ............................................................................................. 9.12 •

Communications Goals................................................................................................... 9.12

Communications Objectives and Messages .................................................................... 9.17

Tactics & Tools.. .............................................................................................................. 9.27

Evaluation...................................................................................................................... 9.35

Implementation.. .................................................................................................................. 9.38 Future Vision.. ...................................................................................................................... 9.40 Literature Cited................................................................................................................... 9.41 Appendix A. Desired Characteristics of JV Matrix for Communications, Education, & Outreach...................................................................... 9.42 Appendix B. Audiences Referenced.................................................................................... 9.43

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Cha pte r O ne

Introduction

Pr incipa l Autho r: Dave S mith

Photo by USF WS


Inside this Chapter Introduction........................................................................................................................... 1.2

Introduction

Plan Overview.. ...................................................................................................................... 1.4 Foundation & Focus of the Plan............................................................................................ 1.5 Mission & Goals.. ................................................................................................................... 1.6 History................................................................................................................................... 1.7 •

1994-2005 Era.................................................................................................................. 1.7

2006-2013 Era.................................................................................................................. 1.7

Administrative Structure.. .................................................................................................... 1.10 Relationship to National Bird Plans & Initiatives................................................................. 1.11 •

North American Waterfowl Management Plan (NAWMP)................................................... 1.11

United States Shorebird Conservation Plan (USSCP)....................................................... 1.12

North American Waterbird Conservation Plan (NAWCP).. .................................................. 1.12

North American Landbird Conservation Plan.. .................................................................. 1.12

North American Bird Conservation Initiative (NABCI)........................................................ 1.13

The Intermountain West Joint Venture (IWJV) encompasses the largest and most ecologically complex region among those defining the 18 U.S. Habitat Joint Ventures Fig. 1. Exceeding 486 million acres, it includes portions of 11 states and a wide variety of habitats important to birds during the breeding, migration, and wintering portions of their annual life cycles. The IWJV boundary encompasses much of the Intermountain Region, from the Rocky Mountains on the east to the Sierras and Cascades on the west, and from the Canadian border on the north to the Mexican border on the south. The IWJV includes portions of 11 Bird Conservation Regions as designated by the North American Bird Conservation Initiative (NABCI) including the entirety of the Southern Rockies/Colorado Plateau and Great Basin, half of the Northern Rockies, and portions of Badlands and Prairies, Sonoran and Mojave Deserts, Sierra Madre Occidental, Chihuahuan Desert, Shortgrass Prairie, Pacific Rainforest, Sierra Nevada, and Coastal California Conservation Regions. The Intermountain West is also characterized by a diverse community of conservation partners that share a vision for healthy landscapes that sustain birds, other wildlife, and people. The IWJV has built a solid foundation for delivery of coordinated bird conservation over the past 18 years by assembling a strong and diverse public-private partnership. The crafters of the IWJV had foresight to include a mix of federal agencies, state agencies, non-governmental 1.2

Figure 1 M  igratory Bird Joint Ventures. Arrow indicates Intermountain West Joint Venture (1 of 18 U.S. Habitat Joint Ventures)

conservation organizations, and for-profit corporations on the Management Board, and then work to extend the IWJV partnership network to a wide array of conservation partners across the Intermountain West. The Joint Venture model is rooted in two simple concepts: 1) science-based habitat objectives result in delivery of focused and successful habitat programs, and 2) partnerships catalyze progress far exceeding what could be attained through independent efforts of individual agencies and organizations. In short, the Joint Venture partnership is more effective and stronger than the sum of its parts.

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INTRODUCTION

Photo by USGS

Achievement of desired future populations of birds and their habitats requires swift and decisive action on many fronts over the next two decades. The core bird conservation plans have been developed, a strong and diverse Joint Venture partnership is in place, and unparalleled funding opportunities for bird conservation exist through a broad array of sources including the North American Wetlands Conservation Act, Farm Bill conservation programs, and a host of other programs and funding sources. However, the threats to bird habitats from development-induced habitat fragmentation, water demands, energy development, and a host of other factors 1.3

that accompany the transitioning economy of the “New West” have never been greater. Habitat conservation must move forward rapidly while the science foundation for bird conservation is strengthened through additional biological planning, conservation design, monitoring and evaluation, and adaptive management. Time is both friend and enemy: ecologically complex habitats still exist and the cost of conservation remains relatively reasonable in many locations, yet the rush of humanity to this region seeking assets ranging from energy to “quality of life” seriously threatens the capability of the landscape to sustain desired bird populations over the long term.

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PLAN OVERVIEW

Photo by Ali Duvall

The 2013 Implementation Plan (Plan) is built upon the model of Strategic Habitat Conservation—the iterative cycle of biological planning, conservation design, habitat delivery, monitoring, evaluation, and research (see Chapter 3). For migratory birds, this involves translating continental bird population objectives to ecoregional scales and identifying the quantity and quality of habitat needed to support priority bird populations at goal levels. The Plan lays out a vision for addressing IWJV science needs in a systematic, step-wise, and transparent manner. This approach is demonstrated through the presentation of population-habitat modeling for specific groups of birds in specific landscapes for the four major bird groups – waterfowl, shorebirds, waterbirds, and landbirds. The science vision and related examples present an approach to establish our priorities for further strengthening IWJV science foundation over the next decade, and carrying out biological planning and conservation design for priority species in key landscapes. The Plan also defines the IWJV approach to delivery of focused habitat conservation at the landscape scale, identifies bottlenecks to delivery, and presents

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solutions to overcoming these impediments through collaboration among members of the IWJV partnership. It provides an overview of some of the programmatic and funding mechanisms needed to influence bird habitats at a landscape scale. Finally, the Plan includes a comprehensive Strategic Communications Plan to promote effective integration of biological planning, conservation design, on-the-ground habitat conservation, and monitoring, evaluation, and applied research among an incredibly diverse and extensive array of conservation partners. The geographic and taxonomic scope of the IWJV requires a much different approach than has been used with the implementation plans of other Habitat Joint Ventures. The Intermountain West is characterized by an extremely high level of habitat heterogeneity (see Chapter 2), which requires establishing a relatively small number of focal species and carrying out biological planning and conservation design in focal landscapes or ecoregions. This precludes the IWJV from developing a synthetic Implementation Plan for all priority birds, JV-wide, at the present time.

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FOUNDATION & FOCUS OF THE PLAN The Plan – the third in the history of the Joint Venture – constitutes a major revision rather than an update of the 2005 Coordinated Bird Conservation Plan (2005 IWJV Implementation Plan). It embodies a new approach and business model for the IWJV, founded on the principles of SHC and rooted in the establishment of JV-wide bird conservation priorities and habitat objectives with explicit connections to continental bird population objectives. The 2005 IWJV Implementation Plan and related 11 state-level IWJV Coordinated Plans for Bird Conservation (IWJV State Plans) identified priority habitats and focal areas, JV-wide. The 2005 IWJV Implementation Plan was truly built from the ground up through an expert opinion process conducted in 2003-2005 through 11 state-level bird conservation working groups or State Steering Committees. The Management Board supported the approach to promote local buy-in and subsequent implementation of Plan recommendations. Based on bird values, threats, and conservation opportunity, the plans identified and classified 13 habitats in 382 Bird Habitat Conservation Areas totaling 128 million acres as either moderate priority or high priority focal areas. The IWJV State Plans established a solid foundation for subsequent efforts by consolidating existing knowledge of avian habitat needs and capturing land cover information for landscapes with biological value. The current Plan builds upon the foundational data presented in the 2005 IWJV Implementation Plan, but progresses from an expert-opinion framework to an explicit modeling framework. Rooted in the principles of SHC and greater quantitative rigor, the current planning is conducted for certain priority birds or bird groups in certain landscapes, rather than in a seamless manner across the entire JV. Biological planning and conservation design toward defensible habitat objectives has been underway for several years and is complete for certain groups of birds in certain landscapes of the Intermountain West. For example, the Plan comprehensively identifies habitat needed to support spring-migrating waterfowl at North American Waterfowl Management Plan goal levels in Southern Oregon and Northeastern California. Likewise, it includes the results of the most detailed conservation strategy ever developed for shorebirds at the Great Salt Lake, one of the most important stopover sites for shorebirds in the Western Hemisphere.

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Remaining data gaps clearly hinder our ability to develop habitat objectives or spatially explicit decision support tools for many priority species, but the IWJV partnership has conveyed a clear message that the results of the population-habitat modeling conducted will be much more compelling than past Joint Venture science products. As such, this Plan consolidates our current knowledge of priority bird species, species-habitat relationships, and the quantity and location of habitat needed to support these populations at goal levels. It will be immediately valuable to habitat managers and conservation practitioners in certain landscapes, and also provide a framework for future efforts to establish habitat objectives for other species in other landscapes. The Plan serves as an important benchmark in the history of the IWJV relative to the establishment of science-based bird conservation priorities. It provides examples of the types of science products that will be developed in the future. It establishes a vision for the IWJV Management Board and partnership to move forward in strengthening our science foundation – embodied by a set of Monitoring and Evaluation priorities that will likely help secure funds for monitoring, evaluation, and applied research. Additionally, the Plan includes a Habitat Conservation Strategy (Chapter 8). While not common in most JV Implementation Plans, this chapter reflects the emphasis and strength of the IWJV partnership in delivering on-theground habitat protection, restoration, and enhancement. Habitat conservation delivery has long been the hallmark of the IWJV partnership. Today, the Management Board allocates a significant amount of funding and staff resources to strengthening the habitat delivery capacity and effectiveness of a wide array of IWJV partners. We are actively engaged with partners in facilitating effective delivery of Farm Bill conservation programs; assisting state fish and wildlife agencies in implementation of their State Wildlife Action Plans; working with the land conservation community to foster strategic habitat protection for priority bird habitats; and delivering a Capacity Grants Program intended to help IWJV partners capitalize on existing funding sources from public and private conservation programs. In summary, the Plan conveys the commitment of the IWJV Management Board to: 1) bridging science with on-the-ground habitat conservation delivery, and 2) maintaining an influential, engaged, and diverse publicprivate partnership.

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MISSION & GOALS

Photo by John Ranlet t

The mission of the IWJV is to conserve priority bird habitats through partnership-driven, science-based projects and programs. We bring people and organizations together to leverage technical and financial resources, building our collective capacity to achieve conservation at meaningful scales. Specifically, the IWJV strives to ensure adequate habitat exists to support priority birds at continental goal levels. In simple terms: The IWJV strives to “set the table� with the quantity and quality of habitat needed to meet the life cycle needs of the birds during the portion of the year they occur within the Intermountain West. The IWJV is committed to conserving habitats in the Intermountain West that are capable of sustaining bird populations at desired levels. To achieve this goal, we will employ the following strategies: 1. Broaden and strengthen public-private partnerships for bird habitat conservation in the Intermountain West. 2. Increase funding for federal and state funding programs essential to bird habitat conservation in the Intermountain West. 1.6

3. Provide funding, foster leverage opportunities, and enhance partner access to federal, state and private funding programs essential to bird habitat conservation in the Intermountain West. 4. Develop a strong science foundation, linking continental, regional, and local population goals and habitat objectives, to inform and empower strategic habitat conservation in the Intermountain West. 5. Employ strategic communications to communicate effectively with target audiences that are necessary to engage for bird conservation. 6. Conduct science based monitoring and evaluation of conservation outcomes capable of measuring their contribution to stated bird population goals and/or habitat objectives. The IWJV’s approach of strengthening its science foundation is necessary to develop specific and defensible habitat objectives related to the outcomes goals stated above. This is being done for certain groups of priority birds in certain landscapes to provide examples of conservation planning that will be conducted in the future.

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HISTORY The IWJV was established in June of 1994 to serve as the implementation arm of the North American Waterfowl Management Plan in the Intermountain Region. Consequently, the primary initial focus of the Joint Venture was conservation of wetlands and associated habitats important to waterfowl.

1994-2005 Era The IWJV developed its first Implementation Plan in 1995, a document that identified nine focal landscapes for waterfowl and provided recommendations for waterfowl habitat conservation. Plan development involved the “collective and collaborative thinking of wetland ecologists, biologists, natural resource managers, conservationists, user groups, private landowners, and local governments as to how the historic values and functions of the wetland ecosystem of the Intermountain area can be maintained, restored and enhanced.” The 1995 Plan nonetheless operated the same then as now, stating: “The Joint Venture is a collaborative effort at all levels. A myriad of participants are already involved and any stakeholder in wetlands issues is welcomed and encouraged to join in this milestone conservation effort.” In June of 1999, the IWJV Management Board voted to expand the mission of the Joint Venture to include conservation actions for all bird habitats within the Joint Venture boundary. The intent was to provide for assistance with implementation of all major bird conservation initiatives, including the North American Waterfowl Management Plan, United States Shorebird Conservation Plan, Partners in Flight, North American Waterbird Conservation Plan, and the Western States Sage Grouse Working Group (an entity then aligned with the North American Grouse Plan). This decision has charted the work of the IWJV for the last 14 years. The IWJV approach during this era was very much centered on building partnerships for on-the-ground habitat conservation, as was stated in an IWJV Management Board policy adopted in 2002: The business of the Joint Venture still centers on assistance with partnership efforts to accomplish on-the-ground conservation for important Intermountain avian habitats. To accomplish this objective our strategic planning must be organized to accommodate and recognize the needs of our state partnerships. Thus, biological planning in the IWJV is rooted in our respective State Steering Committee’s planning efforts. Their work will identify key species, which require specific key habitats, both of which converge at key geographical locations in every state. Any subsequent planning must be driven by the Committees’ work on this basic concept.

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This evolution of the IWJV continued from 2003-2005 with significant investments by the IWJV to establish Bird Conservation Region Coordinators for the Northern Rockies, Great Basin, and Southern Rockies Regions. Three skilled avian ecologists were hired and tasked with advancing bird conservation planning with partnerships throughout each Region. The IWJV became closely aligned with Partners in Flight during this time period and greatly advanced its level of commitment to allbird conservation. This period was also marked by an investment by the IWJV in acquisition and analysis of geospatial data, leading to a seamless land cover data layer for the entire JV Area. The Management Board grew to 29 members by 2005, representing a wide array of conservation interests.

2006-2013 Era This period was marked by significant changes in the Management Board. Out of concerns over the lack of governance procedures, the Management Board developed and ratified a detailed set of Bylaws that govern the partnership. The Bylaws capped the Management Board at 21 individuals and established detailed governance procedures for all other aspects of JV business. In 2008, the JV Coordinator established a process of developing an Annual Operational Plan that links performance objectives to budgetary needs and allocations. This trend of increased accountability fostered a business-like culture that has now become a trademark of the JV. The Board developed a set of Board Member Recruitment and Retention Principles that encourages Board participation at high levels within member organizations (e.g., CEO, Director, State Conservationist, and Deputy Director); this approach has further strengthened the Board by bringing decisionmakers from participating organizations to the JV table. This principle of partnership diversity was also utilized in efforts to energize and support the State Conservation Partnerships (SCPs), formerly called State Steering Committees, and other aspects of the IWJV partnership network. The IWJV continued to maintain a $300,000 annual grants program – now devoted to helping our partners build capacity for bird conservation – an approach that was determined early in the IWJV evolution to be very important to sustained partner engagement.

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HISTORY

NI

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AN

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BIOLOGICAL PLANNING

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Photo by Ali Duvall

MONITORING AND RESEARCH

NG CONSERVATION DESIGN

PROGRAM DELIVERY IMPLEMENTATION

Figure 2 C  onceptual diagram of the Strategic Habitat Conservation process. 1.8

In 2008, the IWJV Management Board made a solid commitment to Strategic Habitat Conservation (SHC), a concept currently being used to move wildlife management beyond the opportunistic and into the strategic realm (see Chapter 3). The document entitled, Strategic Habitat Conservation: Final Report of the Ecological Assessment Team, published by the FWS and U.S. Geological Survey in July 2006, suggests that habitat conservation for all species build on the outstanding model of migratory bird conservation pioneered by NAWMP and the Joint Ventures. To support SHC, the IWJV established fundamental guidelines for the biological planning and conservation design of its four Science Teams: • Establish explicit linkages between populations and habitats through development and use of populationhabitat models (versus establishing habitat objectives based on what we think we can accomplish or what “seems reasonable” to meet the needs of priority species).

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HISTORY • Use these population-habitat models to develop spatially explicit decision-support tools that can help JV partners target habitat delivery. • State all assumptions explicitly so that models can be improved over time through monitoring, evaluation, and applied research. • Implement SHC progressively across the region by BCR/state polygon and sub-region (e.g. priority landscapes for wetland-dependent species) to ensure tangible progress, at least at the landscape scale, in the foreseeable future. For example, detailed SHC-based planning for non-breeding waterfowl and shorebirds is underway at the Great Salt Lake currently and will produce some model-driven habitat objectives in the reasonably near future. • Maintain initial focus on building our science foundation through biological planning and conservation design (e.g., develop models, characterize landscapes, establish habitat objectives, and construct decision-support tools). Support limited and highly selective applied research needed to facilitate modeling in key landscapes. This shift away from project-based monitoring does not preclude occasional support for collaborative inventory, monitoring, or evaluation projects, but dedicated IWJV science funding will remain focused largely on the “front end” of the science equation for the foreseeable future. In 2008, the IWJV launched two major initiatives – the Farm Bill Initiative and State Wildlife Action Plan Initiative – designed to increase JV collaboration with and relevancy to the Natural Resources Conservation Service (NRCS) and the 11 state fish and wildlife agencies. Consequently, the JV shifted priority from funding BCR Coordinators tasked with broadly championing all aspects of bird conservation in their respective Region to acquiring the services of seasoned professionals with significant knowledge of the operations of the NRCS and state fish and wildlife agencies.

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The IWJV Farm Bill Coordinator subsequently implemented a vast body of work that has aligned the IWJV as an instrumental partner with NRCS (and the Farm Services Agency) in implementation of several hundred million dollars of Farm Bill conservation program funding within the Intermountain West annually. The initiative also resulted in development, printing, and distribution of the Field Guide to the 2008 Farm Bill for Fish and Wildlife Conservation, a nationally recognized product of the IWJV and North American Bird Conservation Initiative, written by IWJV Farm Bill Coordinator. He also brokered increased capacity for Farm Bill program implementation, an activity that has resulted in incremental funding devoted to IWJV habitat priorities. Likewise, the IWJV SWAP Implementation Initiative, funded by a foundation grant, greatly accelerated state fish and wildlife agency engagement with IWJV staff, SCPs, and the Management Board. Finally, this evolution resulted in the development of a Strategic Communications Plan (see Chapter 9). Although the IWJV had effectively carried out certain communications activities (e.g., Congressional Communications) over its history, the current plan significantly “raises the bar” for the IWJV and the other 17 U.S. Habitat Joint Ventures, it has already been recognized as something of an “industry standard” for JVs, and provides a detailed roadmap for achieving JV objectives. Most importantly it was developed using the principles of adaptive management or SHC, typically referenced in the science arena.

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ADMINISTRATIVE STRUCTURE The IWJV operates in accordance with a detailed set of Bylaws, U.S. Fish and Wildlife Service (FWS) JV Policy (721 FW 6), its Implementation Plan, and Annual Operational Plans (AOP) that are ratified by the Management Board each year at the Fall Board Meeting. Funding for Joint Ventures is provided through the North American Waterfowl Management Plan/Joint Ventures Program Element of the FWS Migratory Bird Conservation and Management Program in the annual FWS budget. The IWJV receives the second or third highest amount of any JV, slightly less than the Prairie Pothole JV and commensurate with the Atlantic Coast JV. The IWJV also currently receives substantial operational funding from the NRCS and corporate partners. We have received grant funding from other agencies and foundations to facilitate implementation of priorities established by the Management Board (e.g., Farm Bill Initiative, State Wildlife Action Plan Initiative) and will continue to operate in an entrepreneurial manner in the future to best address our objectives across this vast landscape. The annual FWS IWJV funding allocation (approximately $1.05 million per year) is clearly inadequate to meet the full range of IWJV all-bird conservation needs that have been identified and supported by the Management Board, but provides critical support for leveraging other federal, state, and private funds needed to address IWJV objectives. The IWJV core staff is currently comprised of a JV Coordinator, Assistant Coordinator, Science Coordinator, Spatial Ecologist, Farm Bill Coordinator, and Operations Specialist. The staff is a mix of federal employees and contractors working together to carry out the objectives put forth by the Management Board. This 2013 Implementation Plan provides the Management Board and staff with a strategic vision that will support and strengthen the AOPs that have been developed annually since 2008. The IWJV office and Management Board actively work to broaden the external partnership with relevant individuals and organizations. The IWJV maintains strong professional contacts and connections, networking to keep the partners abreast of current conservation issues and techniques. The IWJV office identifies partner capabilities to address our mission and works with partners to address

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its capacity needs through arrangements with partner agencies and organizations. Led by the Congressional Communications Committee of the Management Board and in cooperation with other JVs, the IWJV helps develop common JV messages to Congress and cultivates informational relationships with its Congressional delegation and staff. This work also extends to other relevant national entities. The IWJV is highly successful in this arena with staff connections at many layers of the bird conservation community. Further, we are strongly engaged with state wildlife agencies through the Western Association of Fish and Wildlife Agencies and collaborate with national staff of the Association of Fish and Wildlife Agencies. The IWJV Management Board operates at a very high level due to the establishment of solid governance procedures, the development and approval an AOP each year linking performance objectives to budgetary needs and allocations, and the execution of four Management Board Meetings per year. Since its inception in 1994, the IWJV has actively catalyzed, coordinated and enhanced partnerships among diverse interests. The partnership network of the IWJV includes private landowners, non-profit organizations, local land trusts, state wildlife agencies, land management agencies, and other federal agencies. (See Chapter 9 for more information on the partners.) One of the key mechanisms for partnership coordination is the IWJV’s SCPs. The IWJV has recently rejuvenated its SCPs with staff support, increased communication, and grant funding to address high-priority capacity needs. The SCPs are evolving toward active, self-directed state-level working groups that extend the reach of the IWJV in ways that would otherwise not be possible with limited staff and a large geographic area. Above all, the IWJV is an organization of its partners. The founding Management Board members had the foresight to create 11 state-level working groups and a vast array of partner affiliations at multiple levels (State Conservation Partnerships). The IWJV maintains a headquarters office with a small staff in Missoula, Montana, but the scope of the organization’s work is truly implemented by an active network of conservation partners across the Intermountain West.

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RELATIONSHIP TO NATIONAL BIRD PLANS & INITIATIVES

P h o t o b y S t e v e Te s s m a n n

The IWJV strives to conserve habitat in the Intermountain West as needed to sustain bird populations at goal levels, as defined by the primary continental bird conservation initiatives – the North American Waterfowl Management Plan, U.S. Shorebird Conservation Plan, North American Waterbird Conservation Plan, Partners in Flight, and North American Bird Conservation Initiative. These initiatives, as described below, are at the heart of the IWJV’s bird conservation mission and provide continental connection to our work in the Intermountain West.

North American Waterfowl 

Management Plan (NAWMP)

Vision: To sustain abundant waterfowl populations by conserving landscapes, through partnerships, guided by sound science. Developed in 1986 through collaboration by government agencies and private organizations concerned about declining waterfowl populations, NAWMP was the first continental wildlife conservation plan. The primary goal of the NAWMP is to restore waterfowl populations to levels recorded during the 1970s, a period of relatively high duck abundance. Specifically, the NAWMP vision statement identifies three broad strategies to achieve NAWMP goals: 1) conserve landscapes to sustain waterfowl populations, 2) broaden partnerships, and 3) strengthen the biological foundations of waterfowl conservation. North American Joint Ventures were established in an effort to reach defined waterfowl population goals through regional partnerships to manage and conserve habitats important to waterfowl. The NAWMP has recognized the need to broaden partnerships with other migratory bird conservation initiatives

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encourage and support conservation partnerships with communities. Of note the North American Wetlands Conservation Act was created to provide a funding source to assist the implementation of NAWMP projects. The NAWMP was updated three times since 1986 and then was thoroughly revised in 2012 with an associated Action Plan. A central theme of the current revision is to improve coherence among waterfowl habitat management and conservation, waterfowl harvest strategies, and human dimensions related to the waterfowl management enterprise. The 2012 NAWMP Revision and associated Action Plan adopted three overarching goals: 1. Abundant and resilient waterfowl populations to support hunting and other uses without imperiling habitat. 2. Wetlands and related habitats sufficient to sustain waterfowl populations at desired levels, while providing places to recreate and ecological services that benefit society. 3. Growing numbers of waterfowl hunters, other conservationists and citizens who enjoy and actively support waterfowl and wetlands conservation. An Interim Integration Committee (IIC), prescribed in the Action Plan, has been charged with facilitating the integration of waterfowl management and advancing many of the specific recommendations identified in the Revision and Action Plan. The IWJV is assisting the IIC and will work to support achievement of NAWMP goals and objectives in the future.

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RELATIONSHIP TO NATIONAL BIRD PLANS & INITIATIVES United States Shorebird 

Conservation Plan (USSCP)

Vision: To ensure that stable and self-sustaining populations of all shorebirds are distributed throughout their range and diversity of habitats in the United States and Western Hemisphere, and that species which have declined in distribution or abundance are restored to their former status to the extent possible at costs acceptable to society. Developed as a national partnership between federal and state agencies, non-governmental organizations, and researchers, the United States Shorebird Conservation Plan (USSCP) is committed to the conservation of shorebirds that depend on wetland communities. The USSCP calls for the development of integrated management practices and regional conservation planning to protect shorebirds. The plan identifies goals at several scales, including a hemispheric goal, which addresses the need for international cooperation. National and regional goals and potential management activities are also provided. They generally aim to 1) develop monitoring programs related to shorebirds, 2) conduct research to determine factors limiting shorebird populations, 3) address known limiting factors, and 4) develop coordinated shorebird conservation efforts. Regional shorebird conservation plans under the umbrella of USSCP have been developed including the Intermountain West Regional Shorebird Conservation Plan. The regional plan addresses issues facing shorebird conservation in the Intermountain West through five goals including habitat management, monitoring and assessments, research, outreach, and coordinated planning.

North American Waterbird 

Conservation Plan (NAWCP)

Vision: To restore and sustain the distribution, diversity, and abundance of populations and habitats of breeding, migratory, and nonbreeding waterbirds are sustained or restored throughout the lands and waters of North America, Central America, and the Caribbean. The NAWCP provides an overarching continental framework and guide for conserving waterbirds. It sets forth goals and priorities for waterbirds in all habitats from the Canadian Arctic to Panama, from Bermuda through the U.S. Pacific Islands, at nesting sites, during annual migrations, and during nonbreeding periods. It advocates continent-wide monitoring; provides an impetus for regional conservation planning; proposes national, state, provincial and other local conservation

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planning and action; and gives a larger context for local habitat protection. Specific goals of the NAWCP are to 1) ensure sustainable abundance, diversity, and distribution of waterbird species, 2) protect, restore, and manage key sites and high quality habitat for waterbirds, 3) disseminate information on waterbird conservation to decision makers, the public, and those whose actions impact waterbirds, and 4) coordinate and integrate waterbird conservation efforts, guided by common principles, across geo-political boundaries. The plan also provides a list of scientific information needs, including management-oriented research and ecosystem and landscape issues related to waterbirds. In 2006, the Intermountain West Regional Waterbird Conservation Plan (IWWCP) was developed as a step down plan from the NAWCP. The IWWCP addresses the populations, habitats, and general conservation strategies for the Intermountain West region. The purpose of the IWWCP was to fill knowledge gaps and aid in all-bird conservation efforts of the Intermountain West Joint Venture, 11 States, and other entities associated with the geographic scope of the IWWCP.

North American Landbird  Conservation Plan

Vision: To ensure the long-term maintenance of healthy populations of native landbirds, through the development of voluntary, non-regulatory bird conservation plans that, proactively, provide frameworks to develop and implement habitat conservation actions on species identified as having the greatest need for conservation. Concern about significant population declines for several songbird species, notably Neotropical migrants, resulted in a group of bird conservationists encouraging legislative action for nongame birds. This culminated in an amendment to the U.S. Fish and Wildlife Conservation Act of 1980 and development of Partners in Flight (PIF), an initiative to conserve nongame landbirds in the United States. Guiding principles of PIF included restoring populations of the most imperiled avian species and preventing other birds from becoming endangered -- “keeping common birds common.” This plan provides a continental synthesis of priorities and objectives to guide landbird conservation actions at national and international scales. The PIF 2004 continental plan also identifies seven large-scale avifaunal biomes in North America, encompassing 37 BCRs. Bird species warranting attention due to concern (currently “in trouble”) are labeled “watch list” species, and those that are common

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RELATIONSHIP TO NATIONAL BIRD PLANS & INITIATIVES

Photo by USF WS

but occur primarily in only one of the seven biomes have been identified as “stewardship species.” The plan presents global population estimates for 448 species of North American landbirds as well as continental-scale conservation and stewardship priorities and population objectives for priority species. Priority research and monitoring needs for landbirds are also identified in the plan. In 2010, PIF released Saving Our Shared Birds: Partners in Flight Tri-National Vision for Landbird Conservation. This plan built upon the 2004 plan and presented a comprehensive conservation assessment of landbirds in Canada, Mexico, and the continental U.S. This tri-national vision encompasses the complete range of many migratory species and highlights the vital links among migrants and highly threatened resident species in Mexico.

North American Bird 

Conservation Initiative (NABCI)

Vision: Populations and habitats of North America’s birds protected, restored or enhanced through coordinated efforts at international, national, regional, state and local levels, guided by sound science and effective management.

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Increased interest over the past three decades has stimulated the development of major bird conservation initiatives, including the North American Waterfowl Management Plan, United States Shorebird Conservation Plan, North American Landbird Conservation Plan, and North American Waterbird Conservation Plan. The primary role of the NABCI is to coordinate, not duplicate, efforts of the four major bird plans. Specifically, NABCI is intended to 1) increase the effectiveness of existing and new initiatives, 2) foster greater cooperation among the nations and peoples of the continent, and 3) build on existing structures such as joint ventures, plus stimulate new joint ventures and mechanisms as appropriate. NABCI promotes planning by ecologically distinct bird conservation regions (BCRs) with similar bird communities, habitats, and resource management issues. BCRs are scale-flexible, nested ecological units delineated by the North American Commission for Environmental Cooperation. NABCI has promoted planning by BCRs because they facilitate communication among the bird conservation initiatives, systematically and scientifically apportion North America into conservation units, facilitate a regional approach to bird conservation, promote new and expanded partnerships, and identify overlapping or conflicting conservation priorities.

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Cha pte r Two

C h a r ac t e r i z a t i o n of t h e I WJ V L a n d s c a p e Pr incipa l Autho r: Patr ick D onne lly

Photo by Patrick Donnelly


Inside this Chapter

C h a r ac t e r i z a t i o n of t h e I WJ V L a n d s c a p e

Introduction........................................................................................................................... 2.2 Ecological Setting................................................................................................................. 2.3 •

Northwestern Forested Mountains Ecological Region (162.2 million acres).. ........................ 2.3

North American Deserts Ecological Region (278.9 million acres).. ....................................... 2.4

Temperate Sierras Ecological Region (19.9 million acres)................................................... 2.7

Defining an Ecological Framework.. ...................................................................................... 2.9 •

Global/Intercontinental Scale (Level I Ecoregions).. ............................................................ 2.9

National/Sub-continental Scale (Level II Ecoregions).. ...................................................... 2.10

Regional Scale (Level III Ecoregions)............................................................................... 2.12

Local Scale (Level IV Ecoregions).................................................................................... 2.14

Conservation Estate & Landownership Patterns................................................................. 2.15 Literature Cited .................................................................................................................. 2.17

Few North American Joint Ventures rival the ecological and geo-political diversity of the Intermountain West Joint Venture (IWJV). The IWJV encompasses 486 million acres of the Intermountain West, spanning nearly half the northern temperate zone, from 31.8° N to 48.8° N latitude. Within this region, elevational gradients climb from the lowest point on the continent (–282ft) to over 50 of the tallest peaks (>14,000ft) in the continental United States. Conservation stakeholders within the Intermountain West include eleven western states and a conservation estate defined by a continuous amalgamation of federal/state managed lands and private land ownerships. Outlining the general landscape characteristics of the IWJV is appropriately done from the perspective of a broad ecoregional scale. Ecoregional boundaries are defined by the North American Commission for Environmental Cooperation (CEC) Level I Ecoregions (Fig. 1).

1 Arctic Cordillera 2 Tundra 3 Hudson Plain 4 Taiga 5 Northern Forests 6 Northwestern Forested Mountains 7 Marine West Coast Forest 8 Eastern Temperate Forests 9 Great Plains 10 North American Deserts 11 Mediterranean California 12 Southern Semiarid Highlands 13 Temperate Sierras 14 Tropical Dry Forests 15 Tropical Wet Forests Water IWJV Boundary

2.2

Figure 1 Level I CEC ecological regions highlight the major biomes at the continental scale and provide the broad backdrop to the ecological mosaic of North America, putting the IWJV into context from a continental perspective.

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ECOLOGICAL SETTING At broad ecological scale, the IWJV intersects three Level I Ecoregions: Northwestern Forested Mountains, North American Deserts and Temperate Sierras (Fig. 1). Combined, these regions describe the broad ecological processes that persist across the Intermountain West and inform the potential bounds of ecological threats and limiting factors. Described below are the ecological characteristics identifying those biotic and abiotic factors associated with the CEC Level I Ecoregions. Descriptions of these factors are limited to areas of ecological within the IWJV.

Northwestern Forested Mountains Ecological Region (162.2 million acres)

Within the Intermountain West, this ecological region extends from the Canadian border south to Northern New Mexico. It contains many of the highest mountains of North America and some of the continent’s most diverse mosaics of ecosystem types, ranging from alpine tundra to dense conifer forests to dry sagebrush and grasslands. Major river systems of this region include the headwaters to the Missouri, Columbia, Colorado, and Rio Grande rivers. Surface ownership patterns are predominantly U.S. Forest Service and private land ownership. High topographic relief is the key landscape factor that permits aggregation of these systems into a single level I ecoregion.

Abiotic Setting This ecological region consists of extensive mountains and plateaus separated by wide valleys and lowlands. Most of these plains and valleys are covered by morainic, fluvial, and lacustrine deposits, whereas the mountains consist largely of colluvium and rock outcrops. Numerous glacial lakes occur at higher elevations. Small wetlands and wet meadow complexes exist within valley bottoms. Soils are variable, encompassing shallow soils of alpine sites and nutrient-poor forest soils of the mountain slopes, as well as soils suitable for agriculture and those rich in calcium that support natural dry grasslands.

IWJV Boundary Northwestern Forested Mountains Ecoregion

The climate is subarid to arid and mild in southern lower valleys, humid and cold at higher elevations within the central reaches, and cold and subarid in the north. Moist Pacific air and the effect of orographic rainfall control the precipitation pattern such that both rain shadows and wet belts are generated, often in close geographic proximity to each other. The rain shadow cast by the massive coastal mountains results in a relatively dry climate, and the Rocky Mountains also impede the westward flow of cold, continental Arctic air masses. Mean annual temperatures range between 21°F in the north to 44°F to 50°F in the south. Mean summer temperatures range from about 50°F to 70 F. Annual precipitation varies with elevation, from 102” in the Cascade Mountains to the north, to 15” in other mountainous areas, to between 10”-20” in the valleys.

Figure 2 N  orthwestern forested mountains ecological region within IWJV boundary.

2.3

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ECOLOGICAL SETTING Biotic Setting Vegetative cover is extremely diverse: alpine environments contain various herb, lichen, and shrub associations; whereas the subalpine environment has tree species such as lodgepole pine, subalpine fir, silver fir, grand fir, and Engelmann spruce. With decreasing elevation, vegetation of the mountainous slopes and rolling plains turns into forests characterized by ponderosa pine; interior Douglas fir; lodgepole pine, and aspen in much of the southeast and central portions; and western hemlock, western red cedar, Douglas fir and western white pine in the west and southwest. Shrub vegetation found in the dry southern interior includes big sagebrush, rabbit brush, and antelope brush. Most of the natural grasslands that existed in the dry south have vanished, replaced by urban settlement and agriculture.

North American Deserts Ecological Region (278.9 million acres)

Threats and Human Activities Commercial forest operations have been established in many areas of this region, particularly in the northern interior sections. Mining, oil and gas production, and tourism are the other significant activities. Many lower mountain valleys not currently within the federal conservation estate have been altered at some level as a result of conversion to range and agricultural uses. Expanding urbanization threatens these areas further. Climate change poses the broadest threat to water and wetland resources of the region. Alterations to the distribution and volume of snow pack in conjunction with increased evaporation rates have the potential to impact wetlands, even within areas that are otherwise well protected.

IWJV Boundary North American Deserts Ecoregion

Figure 3 N  orth American deserts ecological region within IWJV boundary.

The North American Deserts ecological region encompasses the majority of the ecological setting within the Intermountain West. The region is distinguished from the adjacent forested mountain ecoregions by its aridity and associated landscapes dominated by shrubs and grasses. Desert river corridors include the Rio Grande and Colorado rivers. Surface ownership patterns are predominantly Bureau of Land Management (BLM), Tribal lands, and private land ownerships. Aridity is the primary ecological factor characterizing this region.

2.4

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ECOLOGICAL SETTING Abiotic Setting The North American Deserts are comprised of a mix of physiographic features but, primarily consists of plains with hills, mountains, and tablelands of high relief. In the north, the flat to rolling topography of the Columbia and Snake River Plateaus consist of loess and volcanic ash deposits on basaltic plains. The Great Basin and its adjacent mountains contain hundreds of north–south trending fault-block mountain ranges separated by broad valleys; the valley floor elevations often exceed 3,000 ft in elevation and many of the ranges surpass 10,000 ft. To the south, the mountain ranges are smaller and less regularly oriented and rise from lower base levels. The lowest basin point, Death Valley, is 282 ft below sea level. Playas systems are abundant in this region. Coalescing alluvial fans characterize transition zones from valley bottoms to mountain slopes. Substantial areas of depositional sand dunes occur in some regions. Landscapes of the Colorado Plateau include uplifted and deeply dissected sedimentary rocks. Soils of the region are dry, generally lacking organic material and distinct soil profiles, and are high in calcium carbonate. This ecological region has a desert and steppe climate, arid to semi-arid, with marked seasonal temperature extremes. The aridity of the region is a consequence of the rain shadow effects resulting from interception of

westerly winter air masses by the Sierra Nevada and Cascade Mountains . The Rocky Mountains to the east also act as barrier to moist air masses that move across the Great Plains from their origin in the Gulf of Mexico. Average annual precipitation ranges from 5” to 14”. The southern deserts have higher average temperatures and evaporation rates, with record-high temperatures in Death Valley reaching 134°F. Some southern areas, such as the Chihuahuan desert, are dominated by a more episodic summer rainfall pattern, while the northern deserts tend toward a winter moisture regime with some precipitation falling as snow.

Biotic Setting Vegetation communities within the desert region are predominantly low-growing shrubs and grasses. Variability in their distribution coincides with corresponding elevational, latitudinal, and geomorphic diversity. In northern desert regions, most native grassland and sagebrush steppe habitats have been converted to agriculture. Areas of the desert Great Basin can be characterized by sagebrush, with shadscale and greasewood on more alkaline soils. Plants of the Chihuahuan desert scrub include tarbush and creosote bush as dominant shrubs with warm season grasses intermixed throughout.

Photo by Patrick Donnelly

2.5

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ECOLOGICAL SETTING

Photo by Patrick Donnelly

Threats and Human Activities Human activities are generally sparse outside of large population centers, but often have substantial impacts on the limited resources of the region. Large federally funded reclamation projects have encouraged development of large-scale irrigated agriculture in parts of the Columbia Plateau, Snake River plain, Wasatch piedmont, upper Rio Grande, and San Luis Valley. Although only a small fraction of the region’s land base is cultivated, irrigated agriculture is the largest user of water resources, which originate largely outside the ecological region as winter snow pack. Hydrologic modifications, salinization, sedimentation, pesticide contamination, and declining water quantity and quality are growing concerns in these areas. Invasive species such as salt cedar are also pervasive in many wetland and riparian areas and threaten habitats associated with these systems. Crops in the north include wheat, dry peas, lentils, potatoes, hay, alfalfa, sugar beets, apples, and hops, while southern irrigated areas mainly produce cotton and alfalfa. The economy of the region has historically been based on primary production, especially from irrigated agriculture and ranching (sheep and beef). The introduction of domestic livestock grazing in the mid- to late-nineteenth 2.6

century has had significant ecological and hydrological effects. Cattle grazing is common throughout the North American Deserts ecological region, as well as in many of the surrounding mountainous regions. Mining is also an important economic factor in the Region. Mining in the area has led to the appearance and abandonment of many small towns devoted to tapping mineral resources such as copper, gold, silver, iron, coal, uranium and salts. Today, tourism and recreation are becoming increasingly important contributors to local and regional economies. Human population density in the region remains relatively low outside large population centers, but persistent urban expansion continues to apply stress to limited water resources of the region. Water rights devoted to agriculture are being converted to domestic water use, limiting conservation opportunities and potentially altering wildlife resource availability by reducing the extent of cropped acreage. Development of alternative energy resources is also expanding throughout the region. As with traditional energy extraction practices, the development of infrastructure associated with these practices increases threats of habitat fragmentation as well as the potential to bird fatalities resulting from impacts caused by wind turbines.

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ECOLOGICAL SETTING Temperate Sierras Ecological Region (19.9 million acres)

Abiotic Setting This ecological region consists of extensive volcanic and fault-block mountain chains and plateaus separated by wide valleys and plains. Most plains and valleys are covered by fluvial and lacustrine deposits, whereas the mountains consist largely of colluvium and rock outcrops. Surface water is limited and many stream and arroyos are intermittent at middle and lower elevations. Soils are variable, encompassing shallow soils of alpine sites and nutrient-poor forest soils of the mountain slopes, as well as soils suitable for agriculture and those rich in calcium that support natural dry grasslands. The climate is subarid to arid in lower valleys, reaching near temperate conditions at higher elevations. Precipitation patterns of the region are episodic in nature driven by Pacific frontal passages and orthographic rain and snow fall during winter months and convective monsoonal events occurring from influxes of moist air off the Gulf of California and Gulf of Mexico. Annual precipitation totals vary by elevation from 10” to 28”. Mean annual temperatures range between 44°F to 50°F.

Biotic Setting

IWJV Boundary Temperate Sierras Ecoregion

Figure 4 T  emperate sierras ecological region within IWJV boundary.

The Temperate Sierras ecoregion falling within the IWJV boundary encompasses the forested mountainous landscapes of Arizona and New Mexico. This area of the region is representative of the ecotones between the North Western Forested Mountains and Temperate Sierra Ecological regions of Mexico. A majority of the ecological characteristics of the North Western Forested Mountains also exists within this region. Ecosystem types range from dense conifer forests, aspen stands, pinion juniper forest, to grassland savannas. Major river systems of this region include the headwaters to the Gila River and major tributaries to the Rio Grande. Surface ownership patterns are predominantly U.S. Forest Service and private land ownership. High topographic relief, persistence of forest and woodland plant community types, and episodic precipitation patterns are the key landscape factors that permit aggregation of these systems into a single level I ecoregion. 2.7

Vegetative cover is extremely diverse: subalpine environments include tree species such as Engelmann spruce, blue spruce, cork bark fir and interior Douglas fir. Open ponderosa pine savannas with grassland understories characterize forest types. Pinion pine, juniper, and oak woodlands on lower slopes transition into semiarid grasslands that dominate valley bottoms and plains. Grassland species in this ecotone are dominated by grama and galleta species. Existing riparian corridors contain galleries of narrow leaf cottonwood, Goodings, and coyote willow. This region represents the northern extent inhabited by many tropical and subtropical migratory bird species (red-faced warbler, painted redstart) that do not occur elsewhere in the United States.

Threats and Human Activities Commercial forestry operations have been established in some areas of this region, but have been less intensive than those conducted in more northerly forests. Past fire suppression policies of the U.S. Forests Service have altered forest density and structure over much of the region. Shifts in forest densities have reduced productivity of understory grasses and increased the risk of catastrophic fires. Long-term and poorly managed grazing on public and private lands have degraded rangeland productivity and severely impacted riparian resources in the region. Climate change poses the broadest threat to water and wetland resources of the region. Alterations to

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ECOLOGICAL SETTING the distribution and volume of snow pack in conjunction with increased evaporation rates have the potential to impact wetlands, even within well protected areas. Although characterizing the ecological diversity of the IWJV in narrative terms provides insight to its complexity, it does not explicitly define the distribution and interspersion of landscape factors and threats necessary for supporting a strategic habitat conservation design. In moving toward a more strategic and scientific approach to landscape conservation we have defined a spatially explicit and ecologically based framework that identifies the conceptual, administrative, and ecological scales appropriate for supporting strategic habitat conservation. Such a framework provides the basis for biological planning and promotes coordination and collaboration among partners in the development and implementation of landscape conservation strategies. The adoption of such a framework promotes the stratification of the landscape into ecologically meaningful units required to initiate strategic wildlife and habitat models and systematic approach to evaluating and ranking conservation priorities. An ecoregional framework also provides a logical (ecologically based) means to summarize, measure, monitor, and aggregate habitat and population metrics across variable landscape scales. Finally, an ecological framework fosters and communicates an ecological understanding of bird conservation, rather than an understanding based on a single-resource, singlediscipline, or single-agency perspective.

Establishing linkages between regional and continental conservation goals for migratory birds is a primary task of Joint Venture conservation science. Consequently, planning scales that are broader and external to the IWJV play an important role shaping our conservation science. However, we focus here on the ecoregional extents that aggregate to the IWJV administrative boundary (Fig. 5).

IWJV Boundary Continental Extent North American Joint Venture Boundaries

Figure 5 IWJV boundary nested hierarchically within the continental scale extent. North American Joint Venture boundaries are displayed as reference.

Photo by Patrick Donnelly

2.8

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DEFINING AN ECOLOGICAL FRAMEWORK An ecological framework should define individual landscapes in an ecologically meaningful way by stratifying landscape variability across the Intermountain West in a spatially explicit manner. Ecological regions (ecoregions) represent the extent that biotic, abiotic, anthropogenic, terrestrial, and aquatic capacities and potentials are similar (Omernik 1987). Ecoregional distributions provide insight to biological planning and landscape/population models; they also inform development of decision support tools within the Intermountain West. Ecoregional extents traverse political boundaries and facilitate bird conservation across state and administrative borders. The framework is flexible and allows aggregation and stratification up and down the hierarchy to encompass both avian population and habitat distribution parameters. The ecoregional classification system adopted for this framework was defined and delineated by the Commission for Environmental Cooperation (1997). The CEC classification was adopted by the North American Bird Conservation Initiative in 1999 and used as the basis for delineating Bird Conservation Regions (BCRs; North American Bird Conservation Initiative 2000). The CEC ecoregions represent four different ecoregional scales within a hierarchical framework of nested ecological units. From ecoregional level I to ecoregional level IV, the spatial resolution of the ecoregions increases

and encompasses areas that are progressively more similar in their biotic (e.g., plant and wildlife) and abiotic (e.g., soils, drainage patterns, temperature, and annual precipitation) characteristics. Below each level is defined and summarized within relevance to the JV.

Global/Intercontinental Scale (Level I Ecoregions) Level I ecological regions (Fig. 1) highlight the major ecological biomes at a continental scale and provide the broad backdrop to the ecological mosaic of North America, putting the IWJV in context at a global or intercontinental perspective. The large area of the North American desert biome internal to the IWJV boundary is informative in regard to the extent of water-limited ecosystems the IWJV encompasses. This perspective supports the emphasis the IWJV has put on waterdependent bird species and associated wetland habitats. Limited wetland habitat continues to be impacted by anthropogenic modifications in this biome with the extent of wetland habitats and wetland productivity trending down (Dahl, 2008). Future projections indicate climate change could modify the hydro-periodicity and distribution of many wetland systems by altering the distribution and volume of snow pack across the Intermountain West (Harpold et al. 2010, McMenamin et al. 2008, Lawler and Mathias 2007).

Photo by Patrick Donnelly

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DEFINING AN ECOLOGICAL FRAMEWORK National/Sub-continental Scale (Level II Ecoregions) Level II ecological regions (Fig. 6) provide a more detailed description of the large ecological areas nested within the level I regions. For example, the North American Deserts Level I ecoregion which intersects the IWJV is composed of two ecological regions at Level II, Cold and Warm Deserts. Level II ecological regions are useful at

national and sub-continental scales when summarizing broad landscape physiographic characteristics, wildlife distributions, and land use practices. The spatial extents of Level II ecoregions are coincident in many cases with BCR boundaries. The IWJV encompasses significant portions of five Level II ecoregions (Fig. 6) and seven BCRs (Fig. 7). Figure 6

 orth American CEC N Level II Ecoregions. Only Level II ecoregions intersecting the IWJV boundary are described in the figure legend.

6.2 Western Cordillera 9.3 West-Central Semiarid Prairies 9.4 South Central Semiarid Prairies 10.1 Cold Deserts 10.2 Warm Deserts 11.1 Mediterranean California 13.1 Upper Gila Mountains 0.0 Water IWJV Boundary

Table 1 Level II ecoregional areas within the IWJV. LEVEL II ECOREGION

ECOREGION ACRES

IWJV ECOREGION ACRES

IWJV %

Mediterranean California

19,474,493

675,291

3.5%

West-Central Semiarid Prairies

188,065,747

2,790,955

1.5%

South Central Semiarid Prairies

119,885,169

13,223,530

11.0%

26,901,624

19,859,713

73.8%

Warm Deserts

158,085,499

32,404,645

20.5%

Western Cordillera

244,731,062

162,224,991

66.3%

Cold Deserts

248,654,382

246,453,973

99.1%

Upper Gila Mountains

Photo by Patrick Donnelly

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DEFINING AN ECOLOGICAL FRAMEWORK

Figure 7 N  orth American BCRs. Only BCRs intersecting the IWJV boundary are described in the figure legend. Badlands and Prairies (BCR 17) Chihuahuan Desert (BCR 35) Coastal California (BCR 17) Great Basin (BCR 9) Northern Pacific Rainforest (BCR 5) Northern Rockies (BCR 10) Shortgrass Prairie (BCR 18) Sierra Madre Occidental (BCR 34) Sierra Nevada (BCR 15) Sonoran and Mojave Deserts (BCR 33) Southern Rockies/Colorado Plateau (BCR 16)

Table 2 Bird Conservation Regions (BCR) within the IWJV.

BCR ACRES

IWJV BCR ACRES

IWJV %

BCR NAME

Coastal California (BCR 32)

47,294,986

712,132

1.5%

Badlands and Prairies (BCR 17)

90,877,294

2,608,428

2.9%

Sonoran and Mojave Deserts (BCR 33)

Shortgrass Prairie (BCR 18)

95,097,525

BCR NAME

Northern Pacific Rainforest (BCR 5) Sierra Nevada (BCR 15)

136,413,183

13,616,123

Sierra Madre 107,015,553 Occidental (BCR 34)

2.11

3,091,304

4,082,088

5,202,338

14,554,203

BCR ACRES

IWJV BCR ACRES

IWJV %

96,704,687

16,234,281

16.8%

141,849,002

21,628,017

15.2%

3.3%

Chihuahuan Desert (BCR 35)

240,066,651

118,918,270

49.5%

3.0%

Northern Rockies (BCR 10) Southern Rockies/ Colorado Plateau (BCR 16)

128,062,728

126,002,050

98.4%

Great Basin (BCR 9)

191,795,903

173,020,527

90.2%

38.2%

13.6%

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DEFINING AN ECOLOGICAL FRAMEWORK Regional Scale (Level III Ecoregions) Level III ecological regions describe smaller ecological areas nested within level II regions (Fig. 8). At this scale Level III ecoregions enhance regional environmental monitoring, assessment and reporting. They allow locally defining characteristics to be identified, and more regionally specific management strategies

6.2.3

Columbia Mountain/Northern Rockies

6.2.4

Canadian Rockies

6.2.5

North Cascades

6.2.8

Eastern Cascades Slopes and Foothills

6.2.9

Blue Mountains

to be formulated. Level III ecoregions provide the biological foundation for stratifying landscapes across the Intermountain West into meaningful units that are appropriate to develop habitat/population model. The IWJV encompasses all or significant portions of 21 Level III ecoregions.

6.2.10 Middle Rockies 6.2.11 Klamath Mountains 6.2.12 Sierra Nevada 6.2.13 Wasatch and Uinta Mountains 6.2.14 Southern Rockies 6.2.15 Idaho Batholith 9.4.3

Southwestern Tablelands

10.1.2 Columbia Plateau 10.1.3 Northern Basin and Range 10.1.4 Wyoming Basin 10.1.5 Central Basin and Range 10.1.6 Colorado Plateaus 10.1.7 Arizona/New Mexico Plateau 10.1.8 Snake River Plain 10.2.1 Mojave Basin and Range 10.2.2 Sonoran Desert 10.2.4 Chihuahuan Desert 13.1.1 Arizona New Mexico Mountains

Figure 8 C  EC Level III Ecoregions, intersecting IWJV boundary. Only Level II ecoregions intersecting the IWJV boundary are described in the figure legend.

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DEFINING AN ECOLOGICAL FRAMEWORK Table 3 Level III ecoregional areas within IWJV extent

LEVEL III ECOREGION NAME

ECOREGION ACRES

IWJV ECOREGION ACRES

IWJV %

Northwestern Glaciated Plains

99,914,031

99,013

0.1%

Northwestern Great Plains

88,151,715

2,691,942

3.1%

California Coastal Sage, Chaparral, and Oak Woodlands

19,474,493

675,291

3.5%

High Plains

70,758,582

3,994,752

5.6%

Madrean Archipelago

18,504,491

1,247,587

6.7%

Canadian Rockies

25,841,279

3,202,103

12.4%

Chihuahuan Desert

126,062,629

16,835,170

13.4%

Klamath Mountains

11,978,288

1,889,825

15.8%

Cascades

11,449,173

2,067,574

18.1%

Southwestern Tablelands

49,126,587

9,228,778

18.8%

Sierra Nevada

13,024,095

4,948,842

38.0%

8,689,192

3,824,863

44.0%

Columbia Mountains/Northern Rockies

44,160,295

20,199,546

45.7%

Mojave Basin and Range

32,022,870

15,569,475

48.6%

Arizona/New Mexico Mountains

26,901,624

19,859,713

73.8%

Middle Rockies

36,128,290

33,488,083

92.7%

Arizona/New Mexico Plateau

37,083,001

35,630,932

96.1%

Southern Rockies

35,975,520

35,246,157

98.0%

Wyoming Basin

32,733,155

32,180,200

98.3%

Columbia Plateau

20,683,605

20,488,914

99.1%

Eastern Cascades Slopes and Foothills

13,857,376

13,730,443

99.1%

Central Basin and Range

76,523,537

76,522,842

100.0%

Blue Mountains

17,484,325

17,484,325

100.0%

Colorado Plateaus

33,318,402

33,318,402

100.0%

Idaho Batholith

14,863,494

14,863,494

100.0%

Northern Basin and Range

35,085,836

35,085,836

100.0%

Snake River Plain

13,226,846

13,226,846

100.0%

Wasatch and Uinta Mountains

11,279,736

11,279,736

100.0%

North Cascades

2.13

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DEFINING AN ECOLOGICAL FRAMEWORK Local Scale (Level IV Ecoregions) Level IV ecological regions describe smaller ecological areas nested within level III regions. Like Level III ecoregions, Level IV provide a detailed stratification of ecological processes that support regional and local conservation objectives. At this scale Level IV ecoregions also provide a meaningful summarization agent, linking ecoregional objectives and local habitat delivery actions. Currently Level IV ecoregions have been developed for 10 of 11 western states within the Intermountain West. The remaining state, Arizona, is expected to be finalized in the near future. The IWJV is unique among the habitat joint ventures when measured by the diversity and extent of state and federally managed lands encompassed. Of the more than 486 million acres that make up the IWJV, over 70% (>335 million acres) are public lands (Figs. 9, 10). Understanding the ecological factors linked to public and private land distribution and the underlying land management practices they represent can provide critical insight to associated levels of land protection and potential habitat quality.

BIA

DOD

Other

USDA

Water

BLM

DOE

Private

USFS

IWJV Boundary

BOR

DOI

State

USFWS

COE

NPS

State Park

WMA

Figure 9 C  onservation estate and landownership patterns in the Intermountain West.

Photo by Patrick Donnelly

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CONSERVATION ESTATE & LANDOWNERSHIP PATTERNS Defining the extent and capacity of the conservation estate based on the single factor of public or private ownership often obscures the perspective of conservation actions. Although public lands in many circumstances are afforded more protection from direct human impacts, they may be more susceptible to indirect and unintended impacts that result from public land management policies. When applied over broad areas consistently over time, such policies can impact millions of acres and act as change agents at a broad ecological scale. The USFS fire suppression policy

provides an example. Implemented from 1935 to 1978, this policy was meant to protect forest resources across the western United States but resulted in shifts in forest density and increased fuel loads that altered the health and structure of many forested habitats across this region. This landscape alteration has undoubtedly impacted bird habitats in portions of the Intermountain West and should be considered a landscape factor in modeling exercises. The USFS currently administers >107 million acres (22.3%) of the IWJV.

Table 4 S ummary of surface ownership within IWJV boundary

OWNER

ACRES

HECTARES

%

51,299

20,760

<0.1%

US Department of Agriculture

256,045

103,618

0.1%

State Park

374,492

151,552

0.1%

Other Govâ&#x20AC;&#x2122;t.

668,862

270,680

0.1%

State Wildlife Management Area

939,096

380,040

0.2%

Bureau of Reclamation

1,398,258

565,857

0.3%

Department of Energy

1,541,764

623,932

0.3%

US Fish & Wildlife Service

3,097,142

1,253,374

0.6%

Department of Defense

9,043,505

3,659,791

1.9%

National Park Service

12,682,798

5,132,567

2.6%

State

22,933,022

9,280,702

4.8%

Bureau of Indian Affairs

33,342,227

13,493,175

7.0%

US Forest Service

107,027,928

43,312,839

22.3%

Private

141,645,141

57,321,984

29.5%

BLM

141,823,200

57,394,042

29.6%

Corps of Engineers

2.15

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CONSERVATION ESTATE & LANDOWNERSHIP PATTERNS Examining the conservation estate from an ecoregional perspective is important when attempting to identify those ecological factors that characterize the extent and interspersion of public and private lands within the Intermountain West. Ecological regions are often associated with persistent ownership patterns that are linked to the social and physical geography of a landscape. The assessment of these relationships often reveals consistent associations of land ownership and land-use practices within ecoregional boundaries. As a result, ownership within ecological regions is often characterized by 1 to a few dominant land-use practices. This characteristic can be illustrated by the distribution of USFS and Bureau of Land Management (BLM) lands among ecological regions within the Intermountain West.

2.16

Because the natural resource missions of these land management agencies are correlated to specific ecological factors (i.e., plant community distributions) their extent is largely coincident with ecoregional boundaries (Fig. 10). In the same manner, the distribution of private lands can also be associated with the extent and inherent value of natural resources. The ecological factors associated with private ownership differ from public ownership factors and were often determined by historic economic values common to Western agricultural development and range land productivity. The outcome of these factors has been a relatively small land base of private ownership within the Intermountain West, but one that potentially represents a disproportionately high bird habitat value. Future biological planning should evaluate this assumption.

BIA

DOD

Other

USDA

Water

BLM

DOE

Private

USFS

Level III Ecoregional Boundaries

BOR

DOI

State

USFWS (1) Idaho Batholith

COE

NPS

State Park

WMA

(2) Northern Great Basin

Figure 10 Land ownership patterns and ecoregional boundaries in the IWJV. 1 = Idaho Batholith, 2 = Northern Basin and Range.

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LITERATURE CITED Commission for Environmental Cooperation (CEC). 1997. Ecological Regions of North America, Toward a Common Perspective, Communications and Public Outreach Department of the CEC Secretariat. Technical Report.

McMenamin S.K., E.A. Hadly, and C.K. Wright. 2008. Climatic change and wetland desiccation cause amphibian decline in Yellowstone National Park. Proceedings of the National Academy of Science USA 105:16988â&#x20AC;&#x201C;16993.

Harpold A. A., S. Rajagopal, I.Heidbuechel, C.Stielstra, A. B. Jardine, and P. D. Brooks. 2010. Trends in Snowpack Depths and the Timing of Snowmelt in the River Basins of the Intermountain West American Geophysical Union, Fall Meeting 2010, abstract #H31I-08.

North American Bird Conservation Initiative (NABCI). 2000. Bird Conservation Region Descriptions, Supplement to the North American Bird Conservation Imitative, Bird Conservation Regions Map. Technical Report.

Lawler J. J. and M. Mathias. 2007. Climate Change and the Future of Biodiversity in Washington. Report prepared for the Washington Biodiversity Council.

2.17

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Cha pte r T hre e

S t r e n g t h e n i n g t h e B i o l og i c a l Fo u n d a t i o n Pr incipa l Autho r s: Jo s h Ve st & Patr ick D onne lly

Photo by USF WS


Inside this Chapter

S t r e n g t h e n i n g t h e B i o l og i c a l Fo u n d a t i o n

Introduction........................................................................................................................... 3.2 Biological Foundation Framework Overview ........................................................................ 3.4 Identify Priorities for Conservation Science.. ........................................................................ 3.5 •

A Strategic Framework for Conservation Science Priorities................................................ 3.5

Biological Planning . ........................................................................................................... 3.10 •

Assess Population Status.. .............................................................................................. 3.10

Determine Population Objectives.. ................................................................................... 3.10

Identifying Limiting Factors............................................................................................. 3.11

Estimating Net Landscape Change.................................................................................. 3.11

Conservation Design........................................................................................................... 3.13 •

Species-Habitat Models.................................................................................................. 3.13

Focus Areas................................................................................................................... 3.14

Characterize Past, Current and Potential Future Landscapes........................................... 3.14

Biological Capacity and Habitat Objectives..................................................................... 3.17

Decision Support Tools................................................................................................... 3.17

Monitoring & Evaluation...................................................................................................... 3.18 Assumption-driven Research ............................................................................................. 3.19 Initiating a Strategic Plan for Science Priorities ................................................................ 3.20 Literature Cited .................................................................................................................. 3.21

The Intermountain West Joint Venture (IWJV) is among the largest and most ecologically diverse Joint Ventures in North America, encompassing parts of 11 western states and 10 different Bird Conservation Regions (BCRs). Consequently, the challenges to sustaining avian populations throughout the IWJV are also diverse and complex. The IWJV has recognized the need for a stronger biological foundation to address increasingly complex challenges to the conservation of birds and their habitats within the Intermountain West. Given the large spatial extent, ecological and political complexity, and a mandate to facilitate the implementation of four national bird conservation initiatives, the IWJV is developing a framework that guides the activities of staff and resources to optimize efficiencies for habitat conservation to achieve sustainable priority bird populations. In order for our conservation actions to be truly effective and measurable, this framework must be developed in the context of science-based principles. Conservation partners in the Intermountain West have been very successful to date in conserving (i.e., protecting, restoring, enhancing, and managing) habitats for migratory birds. Additionally, partners 3.2

have invested considerable resources in bird monitoring, evaluation, and applied research to better understand bird abundance, distribution, and specieshabitat relationships. However, local conservation actions have seldom been linked to continental objectives for migratory bird populations. For example, annual benchmarks for progress have been measured in acres conserved, restored, or enhanced across the Intermountain West versus acres meeting habitat objectives that are linked to continental or regional population objectives. Consequently, conservation partnerships have had limited success in defining or quantifying the results of cooperative conservation efforts to benefit migratory birds. Adoption of a science-based framework to guide conservation partners is needed for the following reasons: 1) the Intermountain West is immense, ecologically complex, and politically diverse; hence, clear consensus is needed on priorities for spending limited resources, 2) tools and techniques that were previously lacking are being developed to quantify and measure objectives within a science-based framework, and 3) the approach allows us to learn from our actions and provides a mechanism to be adaptable and

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INTRODUCTION strategic. Remaining data gaps clearly hinder our ability to develop habitat objectives or spatially explicit decision support tools for avian populations in the Intermountain West. This Plan reflects initial steps by the IWJV to integrate a stronger science-based strategy into its operational structure. As such, this Plan advances the conservation of migratory waterfowl and shorebirds in four continentally significant landscapes. Specifically, efforts seek to identify science-based habitat objectives for springmigrating waterfowl in the Southern Oregon and Northeastern California region, for migrating shorebirds and waterfowl at the Great Salt Lake, for wintering waterfowl in the Columbia Basin, and for shorebirds in the San Luis Valley. Planning efforts in these landscapes recognize their significance to continental populations during appropriate life cycle events. The Plan does not outline a comprehensive conservation strategy for all avian habitats across the entire IWJV, and hence should be viewed as an incremental step toward more strategic bird habitat conservation that serves as an update to objectives identified in prior IWJV plans. However, objectives and strategies identified in this plan will be immediately valuable to habitat mangers in those landscapes and will provide a framework for future efforts to establish habitat objectives for other species or in other landscapes. The IWJV has only recently invested in filling core science capacity needs through the establishment of a Science Coordinator and Spatial Ecologist to facilitate the development of a science-based framework to inform future conservation actions. Although this represents a substantial investment by the IWJV to strengthen the biological foundation, it is an important step. The IWJV will need to commit resources to core science priorities to make substantial and meaningful progress within a science-based framework. First, priorities must be established and key information needs identified and prioritized. Subsequently, IWJV resources should be dedicated to catalyze and leverage opportunities to fill these needs with our partners.

3.3

Shifts in both the conservation paradigm and geopolitical landscapes require the IWJV partnership network to be more accountable with our resources and to not only develop meaningful objectives but also to measure progress toward those objectives. Conservation strategies are intended to evolve from conserving “more” habitat to targeted conservation actions based on a better understanding of what actions are needed, and where, to sustain bird populations. The IWJV intends to address the questions “why”, “how”, “how much”, and “where” to sustain populations of migratory birds through conservation programs: Why: Threats to avian species and their habitats are increasingly complex and urgent. Key threats include land-use changes (e.g., exurban development, energy development, agricultural practices), water supply and quality, invasive species, and climate change. How: The IWJV partnership invests in science to focus resources toward shared priorities. The IWJV will be transparent and explicit in stating 1) population and habitat objectives for migratory birds, 2) what is needed to accomplish these objectives, and 3) how progress will be measured. The IWJV will use the best science available to target conservation efforts and ensure efficiency with limited resources. How Much and Where: Through investments in sound science the IWJV partnership will be able to develop strategic conservation strategies at appropriate ecoregional scales that address key limiting factors impacting priority bird populations. Development of spatially explicit population and habitat objectives linked to expectations of biological outcomes will provide the means to articulate conservation actions in a defensible manner. Working within a strategic framework will facilitate achieving meaningful biological outcomes for priority populations.

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BIOLOGICAL FOUNDATION FRAMEWORK OVERVIEW

Photo by Ali Duvall

• Monitoring and Evaluation– Use monitoring programs to track priority populations; track and evaluate effects of conservation actions on habitats and populations, compare observed with predicted responses, and provide feedback on the effectiveness of conservation actions. • Assumption-driven Research– Encourage, facilitate, and coordinate applied research to test key planning assumptions and reduce management uncertainties.

3.4

MONITORING AND RESEARCH

UA TI EV AL

NG

• Program Delivery–Implementation of habitat conservation and management actions to achieve objectives.

NI

• Conservation Design– Develop and apply spatially informed species-habitat models to identify priority areas for conservation actions and the amount and types of habitat needed to attain population objectives.

AN

• Biological Planning– Compile and assess information on priority species and habitats to provide a biological foundation for prioritizing conservation actions.

ASSUMPTION RESEARCH CONSERVATION DESIGN

• Identify Priorities– Assess priority species and habitats to focus conservation planning and science on. Linkages to continental bird conservation plans, state wildlife action plans, and other ecoregional plans should be assessed within appropriate ecoregional contexts.

BIOLOGICAL PLANNING

PL

The framework for the science-based biological foundation of the IWJV is organized into the following five elements with further detailed descriptions of these elements provided in subsequent sections of this document:

ON

Priorities

PROGRAM DELIVERY

IMPLEMENTATION Figure 1 C  onceptual diagram of the Strategic Habitat Conservation framework.

These elements are organized in an adaptive, iterative cycle following adaptive resource management approach (Fig. 1). This framework encourages “learning by doing,” but with explicit recognition that future iterations will either reduce the uncertainty in planning models or lead to new models and conservation actions. This framework is referred to as Strategic Habitat Conservation (SHC) and is described further in the National Ecological Assessment Team (2006, 2008) reports. Conservation delivery through coordinated implementation of on-the-ground actions through partnerships guided by the biological foundation is a focus of IWJV efforts. The conservation delivery element (i.e., implementation) identified in SHC and Fig. 1 is not included in the biological foundation described here but is addressed in the Habitat Conservation Strategy of the Implementation Plan.

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IDENTIFY PRIORITIES FOR CONSERVATION SCIENCE Implementation of SHC requires thoughtful prioritization of wildlife and their habitats that will be used in the iterative process of conservation planning, implementation, and evaluation. The Intermountain West provides important habitat for dozens of priority bird species identified by the four continental bird conservation plans – North American Waterfowl management Plan (NAWMP), U.S. Shorebird Conservation Plan (USSCP), Partners in Flight (PIF), and the North American Waterbird Conservation Plan (NAWCP). Any of these could serve as the basis for SHC in the Intermountain West. To provide meaningful outcomes the IWJV should provide focused support to supplement the bird conservation planning of its many partner agencies and organizations. Consequently, a continental and JV-wide view of options must be assessed and a set of priorities established for carrying out SHC. Measureable progress in implementing SHC for a subset of priority species will strengthen the collective ability of the JV partnership to deliver targeted conservation as necessary to provide habitat that supports bird populations at continental goal levels. By focusing our efforts on a suite of priority species and habitats within the SHC framework the IWJV will be able to objectively demonstrate progress toward shared goals of the partnership. It is anticipated the ability to measure progress toward shared goals in a science-based framework will result in increased funding, leveraging, and capacity opportunities for avian habitat conservation in the future. Considerations of species and habitat priorities are obscured by the broad ecological and geo-political complexities within the Intermountain West. However, defining focused conservation priorities is a crucial element in our ability to strategically target limited resources and facilitate meaningful and measurable conservation outcomes at ecoregional and continental scales. Formalizing specific priorities will allow us to begin to work within a SHC framework by defining defensible and meaningful priorities for future science investments. To identify priorities, the IWJV will utilize criteria grounded in existing science-based biological planning efforts and principles embraced by the diverse sociological, economic, and environmental interests of the IWJV partnership. To initiate this effort the IWJV is adopting an approach that uses a conceptual model, or framework, to identify and evaluate species and habitat priorities. The process is intended to formalize the method

3.5

of evaluating priorities and communicate the process to the partnership in a concise and transparent manner. Results of this process will: • Identify focused conservation priorities within the context of measurable eco-regional and continental bird population and habitat objectives. • Define criteria necessary to focus goals and objectives of IWJV conservation science and delivery. • Facilitate partnership opportunities and support within a strategic habitat conservation framework. • Produce decision-support tools for proven conservation delivery programs that can effect landscape-scale habitat conservation delivery and inform policy decisions. The first step is to develop a process for identifying species or suites of species that will serve as the basis for SHC. Formalizing this process through the development of conceptual models is a necessary step when scrutinizing conservation priorities. The resulting conceptual framework provides the means to illustrate the logical sequence of criteria used to make selections in a manner that is transparent to all stakeholders involved. Results define focused species and habitat priorities necessary to produce meaningful and measurable conservation outcomes across variable landscape scales. This process draws upon the investment by partners in bird conservation science to date and facilitates a strategic investment of resources to sustain migratory bird populations at a landscape scale– extending beyond traditional jurisdictional boundaries.

A Strategic Framework for Conservation Science Priorities Science priorities will be established through engagement of Technical Committees, State Conservation Partnerships, Flyway Habitat Committees, and Management Board at different points within this process, thereby ensuring that the priorities are representative of and broadly supported by the conservation partnership. A hierarchical framework will be used to identify and evaluate species and habitat priorities for science-based planning (Fig. 1). Each level of the hierarchy serves as a filter and defines the criteria and factors used to evaluate priorities. Level I and level II criteria are considered discrete in nature. To be considered for advancement to successive levels of the hierarchy, species or habitat priorities must be identified within existing plans listed below in Tiers I and II of the framework.

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IDENTIFY PRIORITIES FOR CONSERVATION SCIENCE Level I. Continental Plans from the 4 Bird Initiatives

Level II. SWAPS & Ecoregional Plans

Table 1 C  ontinental and Regional Plans used to identify potential priority bird species in Levels I and II of the IWJV Strategic Framework. FRAMEWORK TIER Level I

PLAN SCOPE Continental

Level III. Extent of Biological & Landscape Information

• North American Waterbird Conservation Plan (NAWCP) • Partners in Flight Tri-national Vision for Landbird Conservation (PIF-TVLC)

Level V. Conservation Delivery or Policy

A species must first be identified in one of the 5 national bird conservation plans (Table 1) to be considered a priority species.

Level II. State Wildlife Action Plans and other Regional Bird Conservation Plans. For priority consideration, a species or habitat association should also be identified as a priority by State Wildlife Action Plans (SWAP) within the Intermountain West. Additionally, a species should be recognized by the USFWS lists for Birds of Management Concern and Birds of Conservation Concern. Central and Pacific Flyway Management Plans will also be assessed as will PIF State and Physiographic Regional Plans for priority species consideration (Table 1). Other regionally-based plans such as The Nature Conservancy’s Ecoregional Plans should also be considered in species and habitat priority assessments.

3.6

• Partners in Flight North American Landbird Conservation Plan (PIFNALCP)

 trategic framework used by the IWJV to identify S species and habitat priorities required to focus conservation actions and sustain priority avian populations within the Intermountain West.

Level I. Continental Bird Conservation Plans.

• North American Waterfowl Management Plan (NAWMP) • United States Shorebird Conservation Plan (USSCP)

Level IV. Conservation Estate

Figure 2

PLAN

Level II

Regional

• State Wildlife Action Plans (SWAP) • USFWS Birds of Management Concern USFWS Focal Species Plans • Intermountain West Regional Shorebird Plan • Intermountain West Waterbird Conservation Plan • Pacific & Central Flyway Management Plans • PIF Bird Conservation Plans for States and Physiographic Regions • TNC Ecoregional Plans

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Once species and habitat lists are compiled from criteria identified in Levels I and II, three categories will be used to identify potential priority species – Highest, High, and Moderate - based on rules and criteria (Table 2) with some modification within each taxonomic group to accommodate differences among and special issues associated with each group or guild. These rules and criteria are generally based on assessing the continental and BCR “concern” for a species and measure of the “responsibility” each BCR has for that species. Concern is generally defined as a combination of the species priority designation within its respective continental bird plan and an assessment of that species population status (e.g., birds of management concern). Responsibility is generally a measure of the significance a BCR has towards meeting the annual life cycle requirements of the species relative to other BCRs. This approach will facilitate the assignment of species to categories based primarily on objective criteria, with each species being evaluated using information from the continental, national, and regional bird conservation plans. Table 2 C  onservation science priority categories and criteria used for bird species in Bird Conservation Regions (BCR) within the IWJV.

PRIORITY

CRITERIA/RULE

HIGHEST

High BCR Concern and High BCR Responsibility AND High or Moderate Continental Concern

HIGH

High Continental Concern and Moderate BCR Responsibility OR Moderate BCR Concern and High BCR Responsibility

MODERATE

Moderate BCR Concern and Moderate BCR responsibility OR High Continental Concern and Low BCR Responsibility OR High BCR Responsibility and Low BCR Concern

3.7

Continental/BCR Concern

IDENTIFY PRIORITIES FOR CONSERVATION SCIENCE

MODERATE

HIGH

HIGHEST

MODERATE

HIGH

HIGH

MODERATE

MODERATE

BCR Responsibility Figure 3 C  onceptual diagram of decision matrix used to assign science conservation priority categories from species identified in Levels I and II of the Strategic Framework based on relationships to Bird Conservation Regions (BCR).

These three categories reflect levels of priority for conservation science, but no ranking is yet assigned to the species within each category. Priority species from all three ranks can be sorted according to the dominant habitat type associations, forming species-habitat suites within each rank. These groupings will allow for the prioritization of habitats according to the distribution of priority species and the identification of issues, goals, and implementation strategies common to species using these habitat types. Subsequently, a subset of surrogate species (e.g., focal species) can be identified for more detailed conservation planning and evaluation of the effectiveness of habitat conservation for the larger set of species associated with that particular habitat type based on successive levels of the Strategic Framework. Given the ecological complexity and extent of the Intermountain West, a focal species approach will be integral to achieving meaningful and measurable progress toward avian habitat conservation. The BCRs serve as primary spatial extents for continental and national bird conservation initiatives and therefore are a useful spatial extent for identifying priorities species andpopulations within the Intermountain West. However, nearly all (≥ 90%) of BCRs 9 (Great Basin) and 16 (Southern Rockies) and half of BCR 10 (Northern Rockies) are contained within the IWJV and these three BCRs comprise 86% of the spatial extent of the IWJV. Thus, biological planning endeavors within these three BCRs will take precedence over smaller BCR components within the IWJV boundary because the IWJV has disproportionate responsibility for these 3 BCRs. Due to the large geographic extent and heterogeneity of BCRs within

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IDENTIFY PRIORITIES FOR CONSERVATION SCIENCE the Intermountain West, sub-BCR spatial extents will be more appropriate for most biological planning endeavors. The North American Commission for Environmental Cooperation (CEC) Level III and IV Ecoregions serve as useful sub-BCR spatial extents because they can easily be aggregated to BCR scales. Chapter 2 provides further detail on appropriate spatial extents for conservation planning in the Intermountain West.

Level III. Extent of Available Biological and Landscape Information. Level III is determined through a ranked value. The volume and utility of science-based biological information for a species is evaluated by its ability to inform strategic biological planning and conservation design. Information and data gaps are identified through literature reviews and data-mining exercises. These gaps are evaluated relative to the capacity required to overcome them and the expected benefits of the conservation actions that would result. Key biological data should include, at minimum, estimates of population size and trends, although information about functional relationships between environmental variables or other limiting factors and demographic parameters is preferable. Information can be extracted from existing regional management or conservation plans for several species which contain various degrees of data and other information describing population sizes, trends, and objectives or descriptions of limiting factors associated with these or other demographic parameters. Ranked assessments of available biological data for potential priority species will directly inform the types of species-habitat models that can be developed within appropriate ecoregional context over identified planning horizons. Assessments of the extent and types of geospatial data required to develop species-habitat models and assessments of current and future landscape conditions within an ecoregional context will also be required. Geospatial data that quantifies landscape composition and habitat conditions for priority species or suites of species will be paramount to developing meaningful and spatially explicit specieshabitat models. The availability, quality, age, and extent of geospatial data will be critical factors in evaluating how and when potential priorities are undertaken in a sequential manner. In some cases, new geospatial data may have to be obtained (e.g., remote sensing) to fully inform redundant biological planning and conservation design efforts. Thus, assessments of both biological and landscape information will be required to distinguish the types of models or tools that can be developed to inform conservation actions as well as identify the information gaps and challenges that must be addressed to develop effective conservation strategies. 3.8

Level IV. Conservation Estate The conservation estate is loosely defined as currently conserved land which benefits one or more bird species. A spatially explicit decision support tool will be used to evaluate the composition of the conservation estate in the context of an individual species or suite of species geographic extent and their life cycle events. Results will measure primary land stewardships within core habitats and identify existing management responsibilities; i.e. Forest Service, BLM, state, or private land ownerships. This evaluation will help to identify appropriate conservation delivery tools and to estimate the impact the partnership may have. Species distributions generally occurring outside the land management responsibility of federal and state agencies will receive additional consideration.

Level V. Habitat Delivery and Policy Level V is determined through a ranked value. Funding sources, political will, and links to proven habitat conservation delivery mechanisms (e.g., Farm Bill, NAWCA) will be considered as factors in this evaluation. The intent of this criterion is to evaluate species and habitats from the perspective of available implementation resources and the degree to which these resources can affect the conservation estate to meet the biological requirements of birds. This evaluation takes into account political factors that influence partnership involvement and also the availability of funding sources and capacity within state and federal programs. However, direct conservation mechanisms may not currently exist to address some limiting factors identified in specieshabitat relationships and may require modifying existing mechanisms or influencing higher policy-level decisions either from within or outside the existing partnership. Identifying connections, or lack thereof, between potential priorities and habitat delivery programs will define the context of science-based biological planning and conservation design.

Science Priorities Through this process, science priorities will reflect a sub-set of the priorities of the IWJV partnership network. Evaluation of potential species and habitat priorities through the Strategic Framework identified above will ensure that capacity and resources are focused on meaningful conservation activities that are important to the partnership and that can achieve measurable progress toward established goals and objectives. Establishing priorities within a strategic framework will enable the IWJV partnership to clearly define meaningful biological objectives and measure progress towards objectives. This will facilitate the partnerships ability to focus resources

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IDENTIFY PRIORITIES FOR CONSERVATION SCIENCE

Photo by Ali Duvall

and capacity on shared priorities and create leveraging opportunities so that shared goals can be accomplished more efficiently. Other organizations and agencies that have been successful in articulating their priorities and use a science-based framework to guide their activities have experienced improved funding opportunities and enhanced credibility among partners. Use of this Strategic Framework will also allow us to formalize the challenges and opportunities to develop effective conservation

3.9

strategies for priority species and habitats within the Intermountain West. Consequently, this information will inform how conservation planning, implementation, and priority research needs are addressed in a successive manner, with limited capacity, in a large and complex Joint Venture. Maintaining a focus on key priorities will ensure the IWJV is value-added to the partnership and able to achieve our program mission.

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BIOLOGICAL PLANNING

Photo by Ali Duvall

Assess Population Status

Determine Population Objectives

Estimating current and historical population levels of priority species at multiple spatial scales provides a measure of the current capability of habitats to support populations and a starting point for determining the difference between current population levels and a population objective. A number of continental, national, regional and state surveys and atlas efforts have documented historical and current distribution and abundance information for bird species in the Intermountain West during various segments of the annual life cycle. This information can be assembled to help assess the current status, distribution, and abundance of priority species including overlap of important areas for these species. Future efforts are needed to estimate population levels for all priority species in the Intermountain West and to continue to refine these estimates based on additional surveys and monitoring. Additional efforts are also needed to better estimate the current state of populations during migration in the Intermountain West.

Population objectives are measurable expressions of societal desires for a given population. They can be expressed as abundance, trend, vital rates, and other measurable indices of population status. These objectives generally represent value-based goals from an estimate of what constitutes a healthy and sustainable population or of how many individuals of a species society wants and will support through conservation. For example, for most waterfowl species, the NAWMP population objectives are based on duck population levels measured in the 1970s when these populations were generally considered to be at desirable levels and provided adequate opportunities for harvest. Partners in Flight, on the other hand, generally set population objectives based on estimated populations at the beginning of the Breeding Bird Survey in the mid1960s.

Although estimates of bird population size are important indices of current state, and hence provide a starting point for evaluating success of conservation efforts, population size is but one measure of population status. Conservation actions that ultimately influence population size do so through influencing demographic parameters such as rates of survival and productivity. Our ability to measure and indicate the status of these demographic parameters will be increasingly important to relate conservation actions to population response. 3.10

Ecoregional or landscape scale objectives in the Intermountain West have been stepped down from continental-scale objectives as stated in bird initiative plans. This stepping-down process has the advantage of linking regional and local conservation actions to continental or national strategies. For some species, particularly land birds, some waterfowl, and some threatened and endangered species, range-wide and ecoregional population objectives have already been developed. Next steps include completion of this process for species where objectives have been established at continental scale but not at BCR or sub-BCR scales. Most bird populations identified in the four continental bird plans are migratory and hence considered federal trust

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BIOLOGICAL PLANNING resources. Identifying any potential objectives for nonfederal trust resources must be accomplished in close cooperation with state wildlife agencies charged with those trust responsibilities. Although a “step-down” approach has much utility, it is based on the assumption that local or regional populations are hierarchical in nature and can be aggregated to a larger spatial scale. However, there is no clear consensus on the functional form of this relationship. For example, there is no easy way to relate continental breeding objectives to populations that migrate through or winter in the Intermountain West. For most species, information is not available regarding seasonal (e.g., during migration and overwinter) survival rates that are necessary for the development of reasonable estimates of migratory or wintering population sizes based on breeding ground objectives. Continuing efforts are needed to address the uncertainties associated with the development of biologically reasonable population objectives at multiple spatial scales, and this constitutes a significant challenge to all Joint Ventures. Surmounting these challenges can only be accomplished through coordination of and investment in science and research efforts with not only adjacent Joint Ventures but with the continental Joint Venture science community. An alternative approach to determining population objectives is to assess the present capability of the landscape to support populations by measuring available habitat and translating it to a population goal through a metric such as density or a species-habitat model. Population objectives can then be set by estimating the expected net change in the capability of habitats in the landscape to support populations based on loss or gain in quantity and quality. However, considerable challenges exist to the development of these landscapebased (“bottom up”) objectives. Principally, the availability and quality of habitat data is often limiting at the scales and resolution necessary to relate to many species in a reliably meaningful way. Also, our understanding of species-habitat relationships at multiple spatial scales is inadequate for many species and therefore limits our ability to develop reliable estimates at large spatial scales.

Identifying Limiting Factors Identification of factors thought to be limiting population growth of species below objective population levels need to be identified or hypothesized. For many species this has already been done by the respective bird initiatives. Designing effective conservation actions for a particular species is impossible without knowing what factors contribute to demographic performance and at what spatial scales those factors operate. These relationships are an

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important component of species-habitat relationships and are necessary for the development of useful decisionsupport tools designed to address these limiting factors. Therefore, the extent and dynamics of limiting factors must be measured through time and spatially explicit linkages of population performance within an ecoregional context must be developed. Once limiting factors have been identified, the hypothesized relationship between the limiting factors and demographic parameters should be tested and evaluated at appropriate spatial scales. Determining the exact cause(s) of population declines (or lack of population growth) is often difficult, but in most cases it should be possible to make reasonable hypotheses that can be explored. Conducting field research may be cost prohibitive to identify precise causes of population decline and in such cases simulation models may be used to assess the likelihood that the proposed mechanism has the ability to limit population growth. In such cases, using a simple rapid prototype model may reduce cost of the modeling exercise while providing quick and useful insights about the modeled system (Blomquist et al. 2010). After limiting factors for any given species or group of species are identified, partners will be able to target conservation actions that address these factors. Consequently, monitoring programs should be designed to evaluate the effectiveness of the conservation actions employed with the results of this evaluation being applied to improve future conservation. Migratory birds are likely to have different factors that are limiting at different times in their annual life cycle. In fact, the most important limiting factors may occur outside of the Intermountain West as is the case with some northern breeding duck and shorebird populations. In these cases, conservation actions should be undertaken by partners in those regions to address those factors. However, IWJV partners still have responsibility for ensuring that habitats in the Intermountain West such as fall and spring migration habitat do not become limiting when the species is restored to objective levels. A detailed assessment of limiting factors may only be possible for a relatively small and hopefully representative group of species. Thus, using a focal species approach, as identified through the Strategic Framework, is a desirable and necessary approach to conservation planning and delivery within the Intermountain West.

Estimating Net Landscape Change Approaching questions associated with habitat and species relationships from a landscape perspective requires an understanding of distribution and extent of those related resources. At ecological scales, these relationships are

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BIOLOGICAL PLANNING intrinsically spatial in nature. Alterations to habitat extents and densities over time are often reflected in changes to the distribution and abundance of associated wildlife species. To inform and model these relationships the IWJV has identified the need to acquire or develop spatial habitat inventories to quantify habitat trends, in some instances over the last 30 years, identify agents of landscape change and inform conservation design and habitat delivery. This information will provide the spatial framework to model landscape ability to support a given number of individuals within a population and determine at what level existing population objectives are being met. Consequently, the IWJV has begun to examine the status and strategies to compile, update, and analyze representative landscape inventory datasets in anticipation of future modeling needs. Although more specific needs for spatially explicit habitat inventories and analysis will be identified once science priorities are known, five datasets are considered essential:

representative of current landscape conditions. At an average age of 30+ years, concern that current NWI data are not fully representative of existing wetland conditions are substantial. The extent of wetland impacts over the past 30 years within the Intermountain West is unclear. The NWI program has established a statistical monitoring protocol to assess national estimates of wetland trends. Although informative at a national scale, the results lack sufficient ecoregional context needed in many cases to inform wetland trends and impacts at regional scales; thus, utility of NWI to inform conservation needs in the Intermounatain West faces some limitations.

1. National Wetlands Inventory (NWI) 2. Continuous landcover datasets: NLCD, ReGAP, TNC landcover data 3. Farm Service Agency (FSA) crop database 4. Satellite and Aerial Imagery: Landsat Thematic Mapper (TM), FSA aerial imagery 5. Digital elevational data: National Elevational Dataset (NED)/LiDAR Of the five data needs identified, NWI data is of particular importance because three of the four continental bird plans are associated with wetland dependent bird guilds and the conservation of their associated wetland habitats. The importance of these habitats is highlighted further when stepped down to the predominantly arid ecoregional setting of the Intermountain West. Initial assessment of NWI status indicates that only 63% of the Intermountain West has digital wetlands inventory available. This status leaves considerable portions of Idaho, Montana, Utah, Colorado, Arizona and New Mexico without digital NWI coverage (Fig. 4). The majority (89%) of NWI data across the Intermountain West is between 25â&#x20AC;&#x201C;40 years old with a mean acquisition date of 1981. Although NWI data provides utility regardless of age, older information is less likely to be

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Age (years) 1-5

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6 - 10

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Figure 4 E  xtent and age of digital NWI coverage currently available across the Intermountain West.

To meet the limitations associated with NWI data in particular, it will be necessary to develop contemporary habitat inventory techniques to update wetland data and conduct spatially explicit wetlands trend assessment within identified priority habitat areas.

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CONSERVATION DESIGN

Photo by Ali Duvall

Conservation design encompasses a series of steps that use the results of biological planning and produce tools that guide decisions about the delivery of conservation actions as efficiently as possible. Ideally, this process also explicitly evaluates the trade-offs involved between species with different habitat requirements instead of considering each species independently. Optimization of conservation strategies to meet the myriad of habitat needs for multiple species will necessarily occur in an iterative and incremental fashion within the Intermountain West due to limitations described above for biological planning inputs. Conservation design in the Intermountain West will involve addressing habitat related limiting factors for bird populations. This will be achieved by understanding and modeling relationships between populations and their habitats, assessing the present and likely future capacity of habitats to support populations, and developing decisionsupport tools to guide habitat conservation actions based on this information. This step includes identification of geographic priorities for conservation. These geographic priorities can be developed from a variety of mechanisms ranging from expert opinion derived focus areas to areas identified from spatially explicit habitat-suitability models that account for a diversity of land management challenges and habitat delivery needs. Current bird conservation planning does not allow for a quantitative assessment of either the capability of landscapes to sustain populations in land use at objective levels or the impact of net change. Current bird conservation planning also is hampered by the inability to assess holistically (i.e., for all species-habitat suites) the current or likely future landscape condition and its ability to support sustainable bird populations. The IWJV is developing bird conservation plans for several sub-BCR areas that identify: 1) priority species and habitats, 2) threats and limiting factors, and 3) population and habitat objectives for bird conservation. The components of conservation design can be described in five steps: develop species-habitat models, develop focus areas, characterize landscapes, evaluate biological capacity and habitat objective, and develop decision-support tools. These processes are discussed in further detail below.

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Species-Habitat Models The list of priority species for a BCR provides a starting point to select a smaller representative subset of species (foal species) to use in conservation design. Focal species as identified through the Strategic Framework are used to represent the needs of larger guilds of species that are assumed to use similar habitats, but are more specialized with respect to habitats, landscape context, and habitat management. The use of focal species is a conservation assessment “shortcut” that reduces the number of models that must be developed and applied to relate the full suite of species to their habitats; however, the assumption that other species will respond similarly to habitat protection, restoration, and management must be evaluated. Developing an efficient Habitat Conservation Strategy requires an understanding of the relationship between populations and habitats. After focal species are selected, the description of the effects of limiting factors on populations should be codified as models – descriptions of what is known or assumed to be true about population-habitat relationships. Models are used to predict factors such as apparent habitat suitability, relative density, or demographic rates. In some cases the primary purpose of developing and applying a model is production of a final product to aid in making decisions, such as identifying priority landscapes for specific conservation actions. Models also may be developed to assess the relative efficiency of different conservation actions. They may also be used to predict the consequences of public policy changes or economic forces that affect habitat. At other times, the primary purpose of a model is to “explore” a relationship, carefully evaluate assumptions, and perhaps change thought processes about a management or conservation action and its consequences for a focal species. The models developed to advance our conservation design efforts will represent a wide array of possibilities. The modeling strategy used for any given focal species will depend upon the level of our understanding of its interactions with its biotic and abiotic environment as well as the amount of empirical data (e.g., survey data) available within appropriate ecoregional contexts. Model types may include conceptual models of species-habitat relationships,

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CONSERVATION DESIGN empirical models, or habitat-suitability index models. Each of these model types has various degrees of utility to inform conservation actions.

Conceptual Models of Species-Habitat Relationships For species lacking adequate empirical data necessary to develop a statistical model, conceptual models can be developed, drawing on the knowledge of experts to derive ranges of parameter values. Such models should be considered hypotheses, and refined based on research projects designed to validate the conceptual hypotheses. Rule sets based on these parameter values can be applied to geospatial information to inform where the hypotheses can be tested.

Empirical Models of Species-Habitat Relationships An example of empirical models commonly used in Joint Venture planning include bioenergetics models that relate food energy supplies to food energy requirements for bird populations within a landscape to establish habitat objectives. These bioenergetics models may be developed in the form of simple daily ration models or more complex spatially-explicit depletion models.

Habitat Suitability Index Models A habitat suitability index (HSI) is a numerical index of habitat suitability on a 0.0 to 1.0 scale based on the assumption that a positive relationship exists between the index and habitat carrying capacity. Historically, models were composed of one or more variables representing life requisites for a species, often called suitability indices. These variables were combined in an arithmetic equation to estimate the HSI. Recent development of HSI models has resulted in models that can be applied to large landscapes using Geographic Information Systems. These models typically rely on data layers derived from remote sensing and other existing spatial data bases or large-scale inventories. Because of the focus on larger scales and their use of GIS technology they can better address ecological and landscape effects on wildlife such as area sensitivity, edge effects, interspersion, landscape composition, and juxtaposition of resources. HSI models can fill a knowledge gap between research and real-world conservation efforts because they can be developed with existing knowledge for scales relevant to conservation planning. A potential weakness is that few such models have been validated (Shifley et al. 2009).

Focus Areas Ideally, designation of conservation focus areas should be driven by empirical assessments of those areas relative to the magnitude of importance for populations of focal species 3.14

identified through the Strategic Framework. Designation of focus areas should ideally also be informed through species-habitat models. Areas for which high concentrations of priority species regularly occur or that are integral to meeting annual life cycle requirements for a significant segment of a focal species population should be considered for focus area designation. Landscapes for which these criteria are met for multiple high-priority species (e.g., Great Salt Lake) should be considered higher priority areas. Thus, reliable estimates of priority species abundance and distribution within annual life cycle segments will be important to identifying focus areas. In the absence of data on bird distribution or demographics, assessments of priority habitat distribution across ecoregional extents should inform focus areas based on assumptions of habitat relationships for priority species. For example, evaluations of wetland densities or complexes and their trends through time across the Intermountain West should inform decisions related to focus areas. In the absence of empirical models of species-habitat relationships, partners can indicate the relative importance of certain landscapes based on expert opinion and the best available information on species and habitat distributions by mapping focus areas and indicating the priority species, threats and needed conservation actions for each. This process was used extensively in development of the 2005 IWJV Implementation Plan. The next logical steps are to identify population objectives and limiting factors for priority species, conduct landscape characterization and assessment to ascertain the habitat needed to sustain these populations, and develop model-driven habitat objectives. The SHC approach requires significant investments in science but can ultimately yield more defensible habitat objectives than have been established through planning based on expert opinion, thereby catalyzing conservation program funding to address habitat objectives.

Characterize Past, Current and Potential Future Landscapes Landscape modeling tools will be utilized to characterize historic and predict future bird habitat status, distribution and trends. Acquisition of satellite imagery is required to conduct change detection analysis necessary for tracking changes in historic land use, urban expansion, invasive species, and other associated habitat stressors (Fig. 5). To conduct these investigations satellite resources from the Earth Resource Observation and Science (EROS) Center of the U.S. Geological Survey will be utilized. EROS currently provides the most comprehensive library of continuous orbital land-based monitoring data available, spanning the time period 1974 to present.

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CONSERVATION DESIGN

Landsat 5 September 21, 1985

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Landsat 5 September 10, 2010

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Figure 5 L  andsat TM satellite data acquired in 1985 (left) and 2010 (right) are used to measure recovery efforts at Owens Lake. Owens Lake is a significant inland water body situated in the Owens Valley between the Sierra Nevada and Inyo Mountains, CA. Historically the lake was an important stopover site for migrating waterfowl and shorebirds.

However, in the early 20th century water sources supporting the lake were diverted, impacting the lake levels and habitat productivity. Beginning in 1999, a plan was put in place to restore the lake region and reestablish habitat for migratory birds. This information will provide the capability to measure historical landscape conditions necessary to establish baseline habitat conditions and habitat delivery objectives (Fig. 6). The ability to forecast future land cover composition will be important in the development of efficient conservation strategies. Thus, identifying landscape level simulation models that are currently available and assessing their utility to evaluate future land cover composition relevant to priority bird habitats will be required.

Figure 6 P  ortion of 1935 historic habitat inventory on the Rio Grande floodplain, New Mexico. The Rio Grande has undergone significant anthropogenic modifications as a result of water “reclamation” impacts. Better understanding of historic conditions that characterized this system has provided essential insight to the levels of habitat modification and is being used to target riparian and wetland restoration opportunities. The inventory was developed using historic 1935 aerial photo prints as a basis to model the extent of habitat features. 3.15

Cultivated/Planted Deciduous Open Tree Canopy Deciduous Shrubland Closed Canopy Deciduous Shrubland Open Canopy Deciduous Shrubland Sparse Canopy Herbaceous Graminold / Forb Vegetation Temporarily Flooded Sandbars Temporarily Flooded Sandbars Sparse Vegetation Temporarily Flooded Sandflats Temporarily Flooded Sandflats Sparse Vegetation Unconsolidated Material Sparse Vegetation Water

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CONSERVATION DESIGN Numerous factors can work independently or synergistically to impact the amount, quality, and distribution of important bird habitats. Some of the primary factors within the Intermountain West are listed below.

Impacts of Urban and Exurban Growth The Intermountain West has experienced dramatic population increases over the past 2 decades. This population increase has not been uniform across the Intermountain West and is linked to availability of natural resources, particularly water resources. Based on current trajectories of human population expansion in the western U.S., human populated areas will increasingly dominate western landscapes at the expense of ranch and farmlands. These farm and ranch properties are currently being converted to small-lot housing projects at unprecedented rates, and the effects on ecological processes are poorly understood (Leu et al. 2008). However, fragmentation of habitat and landscape features is known to have negative impacts on many bird and other wildlife populations. Human population growth in the Intermountain West has had and will continue to have direct and dramatic influences on all other key factors mentioned below.

Invasive Species Invasive plant and animal species often have both direct and indirect impacts on the amount and quality of habitat available to native birds and other wildlife populations. Invasive species can often have cascading effects on the function and integrity of ecosystem processes. Risks of invasive species are often linked directly to land-use patterns and anthropogenic alterations of the landscape.

Water Management and Water Quality The management and availability of quality water supplies is likely the single greatest ultimate factor related to sustaining the majority of priority migratory bird populations in the Intermountain West. Growing human populations will continue to place water resources in the West in direct competition with both agricultural needs and the needs for wildlife populations. Historic water and land use practices in the West have resulted in decreased water quality in a significant number of watersheds through several mechanisms including increased sedimentation and contaminants.

Changes in Land Management • Federal Land Management and Protection Policies Federal lands comprise a substantial proportion (58%) of the Intermountain West. Changes to policies related to protection and land management activities on these federal lands can therefore result in extensive alterations 3.16

to habitat quality and the conservation estate relative to bird and other wildlife populations. • Changes in Agricultural Practices Agricultural areas account for at least 10% of the western United States landscapes and are closely associated with the fertile and highly productive lowelevation valleys and their water resources. Conversion to agricultural production has negatively impacted many bird populations but also has provided important habitat to many others. Changes in agricultural patterns and management practices can greatly alter the availability and quality of these areas for bird populations. For example, conversion from flood irrigation to sprinkler irrigation limits the availability of foraging habitat for many wetland dependent birds such as White-faced Ibis, Sandhill Crane, and Northern Pintail. • Public Land Grazing Practices and Policies Most of the public land acres in the Intermountain West have associated grazing allotments. Historic grazing patterns in many areas have resulted in extensive degradation of habitat quality and suitability for birds and other wildlife. However, proper grazing management can not only be compatible with wildlife objectives but can enhance the quality of habitat for birds and other wildlife species. Therefore, grazing policies and grazing management activities on public lands can have considerable impact on the distribution, amount, and quality of available habitats. • Energy Development The Intermountain West has experienced a dramatic increase in energy development over the past 2 decades. For example, oil and gas development has doubled since 1990. Modifications of landscapes due to energy development may alter both habitat use and vital rates of sensitive bird and other wildlife species. Energy development footprints across the West can therefore impact the amount, distribution, and suitability of habitats for bird populations and other wildlife.

Climate Change Uncertainty in the exact magnitude of predicted changes is substantial, but most global climate change models suggest that global temperatures will continue to rise at unnaturally fast rates, sea levels will rise as a result of melting ice fields, and precipitation patterns will change. Thus, understanding the potential impacts of climate change is important so that appropriate management plans can be developed. Predicted changes in the amount and phenology of snow melt within the Intermountain West will likely have dramatic impacts to exogenous wetland

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CONSERVATION DESIGN systems reliant upon snowpack. A general northward migration of ecosystem types is expected to result from increasing temperatures (U.S. Department of State 2002, Smith 2004). In light of such large potential impacts, partners must be aware of how current conservation actions may be impacted by future system changes. An understanding of species-habitat relationships and assessment of habitat capacity can be combined with these predictions to guide current conservation efforts. • Alternate Management Scenarios Future landscape conditions also are affected by conservation actions taken by the partners to protect, restore, enhance, and manage habitats. The effect of various levels of conservation actions by particular programs can be evaluated, and comparisons of the future capability of landscapes to support populations with or without these programs can be made (e.g., the ability of agricultural landscapes to support early successional species with or without Farm Bill practices). Such analyses can serve as a basis for collaboration with ongoing evaluation programs such as the Conservation Effects Assessment Program of the Natural Resource Conservation Service. Ultimately, the IWJV needs to be able to realistically simulate future land cover conditions under a variety of alternative management scenarios. These scenarios will need to be developed in conjunction with all stakeholders in the areas being simulated. Stakeholders should include joint venture partners as well as representatives from industries and other groups that influence land-use decisions.

Biological Capacity and Habitat Objectives Once species-habitat models for priority species and habitat characterizations are available, carrying capacity can be estimated at appropriate scales. By focusing on demographic parameters instead of just population estimates it will be possible to estimate whether populations are sustainable. In the immediate future, the IWJV will likely be limited in our ability to make such estimates and will have to rely on evaluating estimates of population trends under various management scenarios. However, once this stage is reached, it will be possible to estimate how many acres of habitat are necessary to support a species population target within a region (i.e., what is the population-based habitat objective). Given that all the tools developed to this stage are spatiallyexplicit it will be possible to target conservation to the best areas in order to maintain or increase our biological capacity most efficiently.

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Decision Support Tools The principal questions that must be answered to strategically apply habitat conservation are: • What kind of habitat is needed? • How much habitat is needed? • Where should habitat conservation be targeted? These questions are answered by compiling the biological foundation articulated in biological planning into one or a few products that are easily understood by those making management decisions. For example, the development of maps predicting patterns in an ecosystem is particularly useful because these maps are a means of summarizing the predictions from complex, multidimensional models in a much more easily understandable two-dimensional format. They typically include an assessment of the potential of all habitats to address the needs of a population or set of populations. This means that geographic units with high, moderate, and even low potential to affect populations are included. Decision-support tools are developed to target specific types of management treatments (e.g., sagebrush restoration or wetland protection) that are suited to overcome factors that limit populations of priority species. By building a portfolio of decision-support tools, the IWJV develops the capability to respond quickly to information needs, including opportunities to influence and benefit delivery of programs outside the IWJV partnership (e.g., federal conservation programs). Therefore, the biological foundation should result in the development of spatially-explicit decision support tools that will allow habitat managers and policy makers to: • Determine priority conservation areas for priority species, • Assess the capacity of current landscapes to support populations of priority species, • Resolve conflicts among “competing” habitat types that support priority species, • Predict impacts from land cover changes due to management actions or other causes (e.g., succession, climate change, urbanization) on populations of priority species, • Incorporate adaptive resource management paradigm of explicitly stating assumptions that can be tested and are used within an evaluation framework.

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MONITORING & EVALUATION

Photo by Ali Duvall

The ability to assess the impacts of conservation actions depends largely upon the effectiveness of monitoring programs, needed to demonstrate progress toward the goal of maintaining sustainable bird populations to stakeholders, policy makers, and program managers. Equally important, data from these programs are needed to parameterize models of bird-habitat relationships, evaluate limiting factors, and test assumptions made in the decision-making process. Monitoring may involve assessing demographic parameters (i.e., vital rates) as opposed to counting individuals. Effective monitoring programs allow us to alter future management decisions in a true adaptive management paradigm. Monitoring population and habitat change is a central activity that is critical for providing information for the biological foundation described in this document and for assessing the effectiveness of conservation actions. The IWJV partnership supports the recommendations in the Framework for Coordinated Bird Monitoring in the Northeast (2007) developed by the U.S. North American Bird Conservation Initiative Monitoring Subcommittee. Both of these efforts recommend that bird monitoring move beyond the surveillance type monitoring that is typical of most designs, 3.18

to a paradigm that stresses evaluation of management actions. Note that this shift in paradigm does not negate the ability to assess population trajectories, but it enhances confidence that management actions are having the expected effect on bird populations. This paradigm shift only requires changes in objective setting and design of future bird monitoring projects. Where compatible, the IWJV strongly encourage partners to consider alterations to existing monitoring programs in order to add the valuable component of assessing management effectiveness. The ability to map and model bird abundance and distribution for all priority species will require additional surveys of habitat structure and quality plus data on bird densities. If these additional surveys are planned strategically, they could serve to supplement and validate existing models as well as to begin developing a long-term data set for future analyses. Such data also will be valuable for assessing trends in habitat quality and quantity over time. The Continental Assessment of the North American Waterfowl Management Plan recommended the large-scale monitoring of wetland habitat as a top priority action of the Plan community. Similar efforts in other habitat types would provide a holistic view of change within the Intermountain West.

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ASSUMPTION-DRIVEN RESEARCH A key component of evaluation is the ability to track conservation projects in a way that allows an assessment of the contributions of these projects to the population and habitat objectives of the IWJV partnership. At present, habitat conservation projects by IWJV partner agencies and organizations are tracked annually and cumulatively in a database. This database attempts to record basic information on individual projects including location, acres, and costs. Although this information allows for some coarse assessments of progress by general geographic area, it does not allow for assessments of the amount of habitat conserved or how that habitat conservation could contribute to population objectives. An increased ability to track accomplishments in terms of the specific areas will allow for a better ability to track progress relative to goals. In addition, an increased ability to track other partnerâ&#x20AC;&#x2122;s accomplishments such as those accomplished through the Farm Bill will allow for a better assessment of net habitat change. Without monitoring and research, strategic habitat conservation is not an iterative process by which managers learn and increase their efficiency. Research must be

carried out to evaluate assumptions made in determining limiting factors, developing population-habitat models and decision-support tools, and assessing and predicting effects of management on habitat and species. In the biological planning process, knowledge about populations and habitats are critically applied to answering explicit management questions. In doing so, uncertainties in the biological foundation for management are highlighted. In the absence of perfect knowledge, assumptions, which are essentially testable hypotheses, most be made. However, not all assumptions are equally important. We may consider each assumption in light of two factors: 1) how tenuous it is, and 2) how much better information would affect future management decisions. Assumptions that are both tenuous and high impact are priorities for research. In order for the IWJV to addresses key uncertainties in biological planning, research priorities must be identified and clearly communicated to the broader partnership.

P h o t o b y J o s h Ve s t

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INITIATING A STRATEGIC PLAN FOR SCIENCE PRIORITIES

P h o t o b y B r u c e Ta y l o r

The ecological diversity and scale of the Intermountain West pose considerable challenges to biological planning. Conservation needs currently outstrip the capacity of the IWJV to develop comprehensive conservation strategies across the Intermountain West. Therefore, limited resources must be allocated strategically to maximize the integrity of landscapes and achieve long-term avian population and habitat goals at multiple scales. The IWJV must continue to improve understanding of multi-scale linkages for priority avian populations to effectively implement the continental bird plans. Consequently, further refinement of existing IWJV planning and development of additional biological plans and conservation objectives for priority habitats is required. Development of conservation objectives that are linked to biological outcomes will require prioritization among planning and science investment options through a strategic, science-based framework. At a coarse scale, sagebrush and wetlands are among the highest priority habitats associated with IWJV science and information needs. Near-term evaluations of potential science investment strategies will be focused on these habitats. The IWJV will use the Priority Framework 3.20

described previously and work through a Technical Committee to develop priority science and biological planning strategies. A series of step-down plans will be developed that describes the scope and context of nearterm science investments by the IWJV, the prioritization process, and associated investment strategies. Initiation of identified strategies will require the development of stakeholder working groups and biological planning efforts associated with the identified strategies. These planning efforts will facilitate identification of explicit conservation objectives and implementation plans for the IWJV. The Priority Framework is intended to inform conservation science investments and enable limited resources to be focused on priority habitats and landscapes capable of returning meaningful and measurable biological outcomes for avian populations. By embracing a strategic conservation approach the IWJV will strengthen linkages between continental avian population goals, regional habitat objectives, and local conservation actions. Continued development in biological planning and conservation will ensure that investments made at local levels have relevance to regional and continental scales.

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LITERATURE CITED Blomquist, S. M., T. D. Johnson, D. R. Smith, G. P. Call, B. N. Miller, W. M. Thurman, J. E. McFadden, M. J. Parkin, G. S. Boomer. 2010. Structured decisionmaking and rapid prototyping to plan a management response to an invasive species. Journal of Fish and Wildlife Management 1:19–32. Leu, M., S. E. Hanser, and S. T. Knick. 2008. The human footprint in the West: a large-scale analysis of anthropogenic impacts. Ecological Applications 18: 1119–1139. National Ecological Assessment Team. 2008. Strategic Habitat Conservation Handbook. U.S. Fish and Wildlife Service and U.S. Geological Survey. Available online: (http://www.fws.gov/science/doc/SHCTechnicalHandbook. pdf).

U.S. North American Bird Conservation Initiative Monitoring Subcommittee. 2007. Opportunities for Improving Avian Monitoring. U.S. North American Bird Conservation Initiative Report. U.S. Fish and Wildlife Service, Arlington, VA, USA. Available online: (http://www.nabci-us.org/) Shifley, S. R., C. D. Rittenhouse, and J. J. Millspaugh. 2009. Validation of landscape-scale decision support models that predict vegetation and wildlife dynamics. Pages 415–448 in J. J. Millspaugh and F. R. Thompson, III, eds. Models for Planning Wildlife Conservation in Large Landscapes. Elsevier Incorporated, San Diego, California, USA.of IWJV conservation science and delivery.

Northeast Coordinated Bird Monitoring Partnership. 2007. A Framework for Coordinated Bird Monitoring in the Northeast. Northeast Coordinated Bird Monitoring Partnership Report. Available online: (http://www.nebirdmonirot.org/framework)

3.21

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Cha pte r Four

Wa t e r fow l

Pr incipa l Autho r s: Ma r k Petr ie, Jo s h Ve st, Dave S mith

Photo by USF WS


Inside this Chapter Introduction........................................................................................................................... 4.2

Wa t e r fow l

Non-Breeding Waterfowl....................................................................................................... 4.4 •

Structure of Non-Breeding Waterfowl Plan.. ....................................................................... 4.4

Biological Planning........................................................................................................... 4.4

Conservation Design......................................................................................................... 4.6

Habitat Delivery................................................................................................................ 4.6

Southern Oregon & Northeastern California (SONEC).. ......................................................... 4.7 •

Biological Planning........................................................................................................... 4.7

Conservation Design....................................................................................................... 4.14

Habitat Objectives for SONEC: Spring............................................................................. 4.24

Great Salt Lake.................................................................................................................... 4.25 •

Biological Planning......................................................................................................... 4.25

Conservation Design....................................................................................................... 4.30

Columbia Basin.. .................................................................................................................. 4.37 •

Biological Planning......................................................................................................... 4.37

Conservation Design....................................................................................................... 4.42

Breeding Waterfowl............................................................................................................. 4.53 Literature Cited................................................................................................................... 4.55 Appendix A. Waterfowl Science Team Members.. ................................................................ 4.58

The Intermountain West Joint Venture (IWJV) contains eight areas of continental significance that are recognized in the North American Waterfowl Management Plan (NAWMP 2004), including the Klamath Basin, Malheur Basin, Carson Sink, Ruby Lake, Great Salt Lake and marshes, YellowstoneIntermountain region, Columbia Basin, and Bitterroot Intermountain. The IWJV also is the only US habitat Joint Venture sharing boundaries with both Canada and Mexico. Wetlands of the Intermountain West thus provide habitat throughout the annual cycle of waterfowl–breeding, migration, and wintering. Winter conditions in much of the Intermountain West tend to be relatively severe, and many species of waterfowl migrate out of the Intermountain West for winter. However, some waterfowl species such as Canada geese, Mallards, Redheads, Common Goldeneye, and the Rocky Mountain Population of Trumpeter Swans rely on lake and river systems during winter. Overall, the primary contribution of the Intermountain West to continental populations of waterfowl lies mainly within the breeding and migratory periods of the annual cycle.

4.2

Intermountain wetlands are often highly productive but often set in predominantly xeric landscapes and hence are reliant on annual variation of snow-pack for water supplies. Particularly within the Great Basin, marshes and wetlands are of higher value to waterfowl than are many areas in wetter regions; the very rarity of marshes in a dry region adds to their inherent value. At upper elevations, lakes of glacial origin and wet meadows often provide substantial benefit as breeding habitat but generally minimal value in migration or winter periods. Lower elevation marsh and lake complexes in valley floors thus provide the majority of migration habitat for waterfowl in the Intermountain West. Although the IWJV partnership has been successful at wetland conservation in the Intermountain West, this has occurred without explicit linkages to NAWMP goals. The NAWMP (2004) is predicated on the premise that cumulative effects of many targeted local-scale management actions will ultimately benefit continental waterfowl populations through improvements in recruitment and survival. A primary NAWMP objective is to provide sufficient habitat to

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INTRODUCTION

Photo by USF WS

maintain continental waterfowl populations at goal levels during periods characterized by â&#x20AC;&#x153;average environmental conditions.â&#x20AC;? This IWJV Waterfowl Implementation Plan Update is an initial effort to link local and regional habitat objectives to continental population goals set forth in NAWMP. This initial planning effort focuses on three regions that are recognized as continentally significant by NAWMP and also expected to host the greatest concentrations of waterfowl in the Intermountain West during the nonbreeding period. These include the Columbia Basin of Washington and Oregon, southern Oregon and northeastern California (SONEC) which includes Klamath and Malheur basins, and the Great Salt Lake (GSL) marshes of Utah; all areas have been identified in the NAWMP (2004, 2012). Although the IWJV maintains significant importance to breeding waterfowl (indeed the IWJV was established based largely on its importance to breeding waterfowl), sufficient information is currently 4.3

lacking to establish breeding habitat objectives linked to demographic parameters at meaningful scales. Breeding waterfowl planning in the IWJV will evolve in future planning iterations. Habitat objectives for non-breeding waterfowl were generated based on available information regarding life history requirements for selected waterfowl species, and these objectives are directly linked to regional population objectives. The intent in this plan is to establish explicit regional population and habitat goals and also to assemble recent research results to increase planning effectiveness. A science-based process was used in the planning process for setting objectives, a process that identified assumptions that requiring testing to improve subsequent iterations of the plan. Although the document was written with goals expressed over a 15-year time horizon, the plan is dynamic and will be refined as knowledge of regional waterfowl conservation improves and new spatial data can be incorporated.

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NON-BREEDING WATERFOWL Structure of Non-Breeding Waterfowl Plan In 2005 NAWMP underwent the first assessment in its 20-year history, an assessment focused on Joint Ventures and their collective efforts to meet the needs of waterfowl in North America. The NAWMP Assessment steering committee identified several characteristics believed important to Joint Venture success, and these traits were incorporated into a matrix describing desired characteristics of a Joint Venture implementation plan. Concurrently the USFWS introduced its Strategic Habitat Conservation framework or SHC (National Ecological Assessment Team 2006). The SHC framework promotes a more strategic approach to habitat conservation, where the traditional emphasis on more – more protection, more restoration – gives way to the science of “how much more” and “where?” SHC relies on an iterative cycle of Biological planning, Conservation Design, Habitat Delivery, and Monitoring and Research to achieve landscapes that meet a predetermined goal – e.g. support bird populations at some desired and sustainable level. The Joint Venture matrix and SHC share the same principles for developing effective conservation programs. Moreover, all elements of the Joint Venture matrix can be nested under one of SHC’s four major components. The structure of the IWJV plan (hereafter “JV”) reflects this integration. This plan is structured and organized around three important ecoregions to waterfowl within the IWJV: 1) Columbia Basin, Washington, 2) SONEC, and 3) the GSL. Within each ecoregion, planning is organized by SHC’s major components. Biological Planning and Conservation Design serve as primary headings in the plan, while elements of the Joint Venture matrix occur as subsections under these headings (Fig. 1). Habitat Delivery is addressed in a separate chapter of this current Implementation Plan. Monitoring and Research will be addressed in a separate JV document.

4.4

Ecoregional Planning Unit

Biological Planning

Conservation Design

Spatial Planning Unit

Landscape Characterization and Assessment

Population Objectives and Priority Species

Conservation Goals and Objectives

Special-Habitat Models

Decision Support Tools

Habitat Delivery

Program Objectives

Figure 1 O  rganizational structure of the nonbreeding waterfowl section. Habitat Delivery can be found in the separate Habitat Delivery chapter of the 2012 Implementation Plan Update.

Biological Planning Within the Biological Planning section for each ecoregion the JV waterfowl spatial planning units are generally defined and the seasonal importance of these units to waterfowl is described. This section provides a general description of each planning unit and defines its geographic location within the IWJV. Historic and current habitat conditions in each planning unit are compared and habitat changes evaluated from a waterfowl perspective. In many cases it is simply not possible to restore landscapes in ways that closely resembles ‘historic” conditions. Irreversible changes in hydrology, alternative land uses, and political realities often prevent the re-creation of historic conditions on anything but very small scales. Still it is important to understand how waterfowl were adapted to these historical landscapes and to design conservation programs that reflect those adaptations. In the Biological Planning section, population objectives for priority waterfowl species are also established. Factors thought to limit these populations arestated explicitly in the context of species / habitat models. Similar limiting factors are identified for each ecoregion, and similar species/habitat models are used to understand relationships between nonbreeding waterfowl and their habitats. Therefore, an overview of these limiting factors and modeling process is provided here.

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NON-BREEDING WATERFOWL Limiting Factors/Speciesâ&#x20AC;&#x201C;Habitat Models: TRUEMET This plan addresses the biological needs of waterfowl during the non-breeding period, which includes fall and spring migration as well as winter. Food availability is a key factor limiting waterfowl during migration and winter (Miller 1986, Conroy et al. 1989, Reinecke et al. 1989), and habitat conditions during the non-breeding period may influence reproductive success (Heitmeyer and Fredrickson 1981, Kaminski and Gluesing 1987, Raveling and Heitmeyer 1989). The JV assumes that food limits populations during migration and winter. Specifically, food is the primary need of waterfowl during migration and winter. Providing adequate foraging habitat for priority species will ensure that survival outside of the breeding season does not limit their population growth. Joint Ventures have been encouraged to develop biological models that explicitly link bird population objectives to habitat objectives, and to undertake rigorous analysis of habitat carrying capacity based on these population-habitat models (NAWMP Assessment 2007). The bioenergetic model TRUEMET (Central Valley Joint Venture 2006) was used to evaluate current habitat conditions for priority waterfowl species and to inform future habitat objectives. TRUEMET is a type of daily ration model which provides an estimate of population food-energy demand and food-energy supplies for specified time periods (Fig. 2). Population energy-demand is a function of periodspecific population objectives and the daily energy requirement of individual birds. Population energy supply is a function of the foraging habitats available and the biomass and nutritional quality of foods contained therein. A comparison of energy supply vs. energy requirements provides a measure of carrying capacity relative to bird population objectives.

Results produced by TRUEMET are a function of model structure and parameter inputs. Thus, two types of inherent error must be considered in any such modeling exercise: conceptual (theoretical assumptions used to build the model) and empirical (the availability, precision and accuracy of data used for model inputs). Model structure was determined by the set of rules that dictated how birds foraged. It was assumed that: 1) birds were ideal free foragers (Fretwell 1972) and were not prevented from accessing food resources due to interference competition; 2) birds switched to alternate foods when preferred foods were depleted below some foraging threshold; 3) the functional relationships that determined population energy demand and population food energy supplies were linear; and 4) that there was no cost associated with traveling between foraging patches. Empirical work has shown these assumptions to be false in some cases (Nolet et al. 2006); but valid in others (Goss-Custard et al. 2003, Arzel et al. 2007,). Additional studies of waterfowl foraging ecology could either improve model structure or confirm the validity of the daily ration approach. Although the model can be used to evaluate carrying capacity of existing landscapes, it can also be used to predict how changes in policy, land use, or habitat programs might impact priority bird species. Six explicit inputs are required for each model run: 1. Time periods being modeled. 2. Waterfowl population objectives. 3. Waterfowl daily energy requirements. 4. Amount of each habitat type available in each time period. 5. Biomass of food in each habitat type on day one. 6. Nutritional quality of each food type.

Time Periods Being Modeled

Figure 2 H  ypothetical population food energy demand vs. population food energy supply as estimated by the TRUEMET model in kilocalories (kcal). Food energy supplies are deemed adequate if supply exceeds demand. 4.5

Within TRUEMET the user must first define the length of the non-breeding period (e.g. October to April). The non-breeding period can then be sub-divided into as may time segments as desired. For example, population energy demand vs. habitat energy supply may be modeled on a daily, weekly, or monthly basis within the larger nonbreeding period. The length of these time segments is usually determined by data restrictions. Modeling energy demand vs. supply on a bi-weekly or monthly basis is most common (e.g., Central Valley Joint Venture 2006).

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NON-BREEDING WATERFOWL Waterfowl Population Objectives Waterfowl population objectives used in TRUEMET are specific to each time segment (e.g. the month of October). Ideally, these time specific population objectives are derived from the NAWMP.

Waterfowl Daily Energy Requirements Within TRUEMET the user may sub-divide waterfowl into separate foraging guilds that have access to specific foraging habitats. For example, population objectives for each dabbling duck species may be combined into a single “dabbling duck” guild. TRUEMET requires an estimate of the daily energy requirement of the average bird in each foraging guild. To estimate the daily energy requirement of this average bird a resting metabolic rate (RMR) is calculated using the following equation (Miller and Eadie 2006), where RMR is multiplied by a factor of three to account for energy costs of free living: RMR (kJ/day) = 433 * (body mass in kg)

0.785

Body mass is equal to the average body mass of birds in a foraging guild within a specified time period.

Habitat Availability and Biomass and Nutritional Quality of Foods TRUEMET requires information on the availability of waterfowl habitat, the biomass of foods in those habitats, and the nutritional quality of those foods. Habitat availability is a function of habitat area (e.g. acres) and the ability of waterfowl to access foods produced in a habitat type. For example, managed wetlands may total 500 acres but these habitats may only become available after October 1 when they are intentionally flooded. Estimates of Food biomass are obtained by local sampling or from published sources. However, waterfowl abandon feeding in habitats before all food is exhausted because at some point the costs of continuing to forage on a

4.6

diminishing resource exceeds energy gained; this value is called the giving-up-density or foraging threshold (Nolet et al. 2006). For example, Mallards feeding in dry fields in Texas reduced corn densities to 13 lbs / acre before abandoning fields (Baldassare and Bolen 1984). Consequently, biomass estimates were adjusted by subtracting published estimates of giving up densities– 13 lbs/acre for agricultural foods (Baldassare and Bolen 1984) and 30lbs/acre, for seed resources in wetland habitats (Naylor 2002). Although waterfowl carrying capacity is strongly dependent on food biomass, the energy or calories provided by these foods is also important. True metabolizable energy (TME) provides a measure of the caloric energy waterfowl are able to extract from foods.

Conservation Design The Conservation Design section includes a description of existing landscapes and their capacity to support waterfowl populations at desired levels. The section also includes a set of explicit conservation objectives. Joint Ventures have been encouraged to undertake a rigorous analysis of habitat carrying capacity for waterfowl (NAWMP Assessment) because such analyses can help evaluate landscape capacity to support waterfowl populations at NAWMP goals and thus inform conservation objectives and strategies. Waterfowl carrying capacity was evaluated for each spatial planning unit, including in some cases how this may have changed over time. Conservation objectives and strategies that were at least partly based on these carrying capacity results were subsequently developed.

Habitat Delivery Habitat delivery is addressed in the Habitat Conservation Strategy (Chapter 8) of this Implementation Plan. As part of that chapter, conservation goals, objectives, and actions are defined addressing waterfowl habitat in the SONEC and GSL landscapes.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Biological Planning Spatial Planning Unit The SONEC planning unit includes all major wetland complexes in the intermountain basins of southern Oregon, northeastern California and extreme northwest Nevada in the northwest portion of the hydrologic Great Basin (Fig. 3), and the description here relies heavily on Fleskes and Battaglia (2004). The SONEC region comprises approximately 10% of the Great Basin, although waterfowl habitat covers considerably less area. SONEC is generally “basin and range” topography with major uplift regions running mostly north and south. Average basin altitude is 4,000 ft above sea level and most wetlands important to waterfowl are in these basins. It contains watersheds that are connected to the Pacific Ocean (e.g., Klamath and Pit Rivers) as well as those that drain into terminal closed basins.

minimums averaging 19 °F. As in most dry climates, daily temperatures vary widely with rapid cooling after sunset leading to cold nights and rapid warming producing high daytime temperatures. Water supplies derive mainly from snowmelt, and wetlands experience wide fluctuations in hydrology that are directly related to annual snow pack. Malheur Lake for example, which is essentially a marsh, was dry and being farmed in 1934 but had increased in size to approximately 40,000 acres by 1938 (Duebbert 1969). The importance of SONEC habitats to waterfowl was emphasized by Kadlec and Smith (1989) who stated: “In contrast to the perception that the region is a “desert” with little value to waterfowl, the reality is that the marshes and wetlands are of higher value to waterfowl than are many areas in wetter regions. In fact, the very rarity of marshes in a dry region adds to their value.” Historically, peak waterfowl abundance in SONEC likely occurred during fall and spring migration. Wintering waterfowl populations were probably small as minimum winter temperatures are well below freezing and most wetland habitats were likely frozen. In most years fall migrating waterfowl likely would have encountered relatively dry landscapes with most available wetland habitat occurring in terminal basins. These were likely permanent or semi-permanent wetlands as this region experiences one of the highest evapotranspiration rates in North America (Engilis and Reid 1996). During fall migration it seems likely that waterfowl were historically confined to a few large wetland complexes.

Figure 3 S  patial planning unit for the southern Oregon and northeastern California (SONEC) region and subregion within SONEC.

The complex topography of SONEC produces highly variable and localized climate conditions with some of the most extreme weather in California and Oregon occurring there. Temperatures are highly variable throughout the year with summer maximums averaging 91°F and winter 4.7

Although changes in land use have greatly altered the terminal basins of SONEC, such areas continue to support nearly all of the region’s fall migrating waterfowl. P h o t o b y I WJ V Virtually all of these habitats are publicly owned with very few wetlands occurring on private lands during fall. This provides a stark contrast to other areas of the U.S. where the bulk of fall migration habitat is provided on private lands (e.g., the California Central Valley). Moreover, the importance of publically owned habitats in SONEC places the JV in a unique conservation planning position. Although most Joint Ventures incorporate public lands into overall

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) implementation plans, planning for fall migrating waterfowl in SONEC is largely synonymous with planning on publicly managed lands. Historically, habitat conditions during spring migration varied widely among years, mostly in relation to snow pack. In addition to permanent or semi-permanent habitats, many SONEC terminal basins contain shallow lakes and palustrine wetlands that were fed almost exclusively by snowmelt and which likely provided significant food resources. When snowfall was abundant spring migrants would have access to large areas of these seasonally flooded habitats. In contrast, shallowly flooded habitats may have been limited in years of low snowfall. Regardless of snowfall most of these shallowly flooded habitats were probably dry by fall. Most of SONEC spring-flooded wetland habitat is currently used for hay production and grazing. The Chewaucan marsh provides a typical example. The Chewaucan River P h o t o b y M i ke S h a n n o n drains into the Upper and Lower Chewaucan Marshes before terminating in Lake Abert, the largest saline lake in the Pacific Northwest. Historically, the Chewaucan Marsh totaled about 30,000 acres of emergent marsh and provided significant habitat for spring migrating waterfowl in years of high runoff. Today the former Chewaucan Marsh is devoted to forage production for cattle and is grazed and hayed annually. However, every spring land owners divert water across much of the Marsh through flood-irrigation. Spring migrating waterfowl make extensive use of these flood-irrigated lands (Fleskes and Yee 2007, Fleskes and Battaglia 2010). Flood irrigation is a common practice throughout SONEC and occurs mostly on altered seasonal wetlands that were historically dependent on natural flooding from snowmelt. For example the Silvies River Floodplain near Malheur Refuge and northern portions of the Goose Lake Basin contain extensive tracts of flood-irrigated lands, and flood irrigation may have increased reliability of spring habitat in SONEC. Private landowners have developed the infrastructure needed to divert water over large areas of hayed and grazed lands. Prior to settlement many of these former wetlands may have experienced little or no seasonal flooding in years of low snowfall. Today the practice of 4.8

flood irrigation may result in more shallowly flooded habitat than historically occurred under similar snow pack levels. However, it seems unlikely that the increased “stability” of spring habitat in SONEC compensates for the overall loss of migration habitat within this part of the Pacific Flyway.

Summary Points 1. Historically, fall migrating waterfowl in SONEC probably depended on a small number of permanent to semi-permanent wetlands that occurred in terminal basins. The same is largely true today. 2. Virtually all fall migration habitat in SONEC is located on public lands. Private lands provide relatively little fall migration habit relative to other areas of the U.S. 3. Most of the seasonal emergent marsh wetland habitats that were historically important to spring migrating waterfowl in SONEC are currently part of working ranches managed for hay and fall/winter grazing. However, much of these agriculturally managed wetlands are flood irrigated and today provide important spring migration habitat.

Population Objectives and Priority Species The SONEC region experiences peak waterfowl populations in fall and spring. Wintering waterfowl populations in these areas are relatively small because low temperatures make most wetland habitats unavailable. Fitting migration data to a NAWMP midwinter objective to generate monthly population objectives as done for the CB is therefore not appropriate in SONEC. As a result, the JV used alternative methods for establishing monthly population objectives for SONEC that still maintained a strong connection to the NAWMP.

Ducks – Fall and Winter The fall-winter period was defined as September 1 to January 31. The majority of fall and winter waterfowl habitat in SONEC occurs on public lands (see discussion under “Spatial Planning Units”). As a result, establishing waterfowl population objectives during fall and winter is largely synonymous with establishing population objectives for important public habitats in SONEC. To date, fall and winter population objectives have only been established for the Lower Klamath National Wildlife Refuge (Lower Klamath) and the Tule Lake National Wildlife Refuge (Tule Lake). Although these two refuges account for only a small fraction of the SONEC landscape they support a significant fraction of the waterfowl that use SONEC in fall and winter (Kadlec and Smith 1989, Fleskes and Yee 2007).

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) In order to link management efforts for ducks at Tule Lake and Lower Klamath to the NAWMP, waterfowl surveys conducted during the 1970’s were used to establish duck population objectives. Efforts to survey waterfowl populations at Tule Lake and Lower Klamath began as early as 1944. Waterfowl were primarily censused from the ground until 1953 when refuge biologists began conducting two or more aerial surveys per year. Beginning in the early 1960’s both ground and aerial surveys were conducted bi-weekly. Waterfowl surveys began in late August or early September to coincide with arrival of early migrants and continued through late April or early May. Although aerial surveys have continued at both refuges, ground surveys were largely discontinued after 1977 (Gilmer et al. 2004). Bi-weekly aerial surveys from the 1970’s were used to develop population objectives for ducks at Tule Lake and Lower Klamath for each two week interval between September 1 and January 31. Population objectives for each interval were based on survey counts from 1970 to 1979 and were set equal to the 75th percentile of these counts (Tables 1, 2). The 75th percentile rather than the mean was chosen because mean populations based on aerial surveys often are negatively biased when not all birds are counted, and because annual waterfowl use of the refuges may frequently exceed population objectives that are based on a ten year mean.

Table 1 F  all and winter waterfowl population objectives for Tule Lake National Wildlife Refuge. DATE

a

SWANS

Sept 1

53,100

4,270

14,680

0

Sept 15

54,725

2,990

10,630

0

Oct 1

292,200

6,998

37,460

0

Oct 15

281,100

10,730

82,170

0

Nov 1

765,901

16,440

136,413

260

Nov 15

268,328

11,088

146,605

713

Dec 1

193,700

3,825

50,275

1,230

Dec 15

262,400

2,200

64,608

1,125

Jan 1

37,015

193

9,240

640

Jan 15

91,955

675

4,040

4,205

Divers include Canvasback, Redhead, Ruddy Duck, Bufflehead, Ringnecked Duck, Goldeneye, and Scaup

Table 2 F  all and winter waterfowl population objectives for Lower Klamath National Wildlife Refuge. DATE

a

DABBLERSA

DIVERSB

GEESEC

SWANS

Sept 1

213,521

2,270

7,640

0

Sept 15

219,869

1,791

5,820

0

Oct 1

401,738

3,708

51,610

0

Oct 15

597,010

7,385

36,095

0

Nov 1

597,536

6 ,313

34,160

1,545

Nov 15

487,361

5,783

46,855

3,193

Dec 1

372,560

1,250

19,475

930

Dec 15

198,118

855

12,488

1,398

Jan 1

10,594

160

7,430

2,490

Jan 15

27,171

305

12,990

7,211

Dabblers include Mallard, Gadwall, Northern Pintail, Green-winged Teal, Cinnamon Teal, and Northern Shoveler

b

c

4.9

GEESEC

Geese include Canada Goose, Cackling Goose, Greater White-fronted Goose, Lesser Snow Goose, and Ross’ Goose

Geese and Swans – Fall and Winter Although duck population objectives were derived from the 1970’s, population objectives for geese and swans were based from 1990 to 1999. Goose and swan populations in the Pacific Flyway have undergone major changes in size and distribution since the 1970’s, so more recent counts of geese and swans were used to establish population objectives. Bi-weekly aerial surveys from the 1990’s were used to develop population objectives for geese and swans at Tule Lake and Lower Klamath for each two week interval between September 1 and January 31. Population objectives for each interval were based on survey counts from 1990 to 1999 and were equal to the 75th percentile of these counts (Tables 1, 2)

DIVERSB

Dabblers include Mallard, Gadwall, Northern Pintail, Green-winged Teal, Cinnamon Teal, and Northern Shoveler

b

c

DABBLERSA

Divers include Canvasback, Redhead, Ruddy Duck, Bufflehead, Ringnecked Duck, Goldeneye, and Scaup

Geese include Canada Goose, Cackling Goose, Greater White-fronted Goose, Lesser Snow Goose, and Ross’ Goose

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Ducks - Spring NAWMP mid-winter objectives alone are of limited value where peak waterfowl populations occur in fall or spring. However, mid-winter population objectives can be used to help establish a spring population objective if the probability that birds will transition from a wintering area to a spring staging area is known (Petrie et al. 2011). Nearly half of all ducks that migrate through SONEC in spring are Northern Pintail (Fleskes and Yee 2007). During winters 2000–2003, 140 female Northern Pintails were captured in the Central Valley and fitted with backmounted satellite transmitters (Miller et al. 2005). One objective of the study was to identify spring migration routes and staging areas used by pintails. Eighty-percent of all pintails marked in the Central Valley used SONEC in spring. Four wintering areas that potentially “supply” SONEC with spring migrating waterfowl were identified: 1) the West Coast of Mexico including the Baja Peninsula, 2) the Central Valley, 3) California counties that lie outside of the Central Valley, and SONEC, and 4) Oregon and California counties within SONEC. NAWMP mid-winter population objectives have been established for most of these areas (Koneff 2003). If 80% of the ducks wintering in these areas use SONEC in spring (the value estimated for Central Valley Northern Pintails), the JV can begin constructing spring population objectives for SONEC. The JV initially focused on pintails before expanding the discussion to other waterfowl species.

south to Mexico’s west coast did not use SONEC in spring (Haukos et al. 2006). Although some pintails wintering on the Baja Peninsula or Mexico’s west coast undoubtedly migrate through SONEC, this number is assumed small. For the purpose of establishing spring population objectives for SONEC it was assumed that pintails wintering in these areas do not use SONEC in spring. Central Valley The Central Valley was defined as all California counties included in the Central Valley Joint Venture (CVJV) primary, secondary, and tertiary areas of interest (Central Valley Joint Venture 2006; Fig. 4). The NAWMP midwinter population objective for Northern Pintails in the Central Valley Joint Venture region is 2,394,926 (Table 3). Eighty percent of all Northern Pintails that winter in the Central Valley use SONEC in spring (Miller et al. 2005). Thus, the JV assumes that the Central Valley contributes 1,915,941 birds to the spring population in SONEC when Northern Pintails are at NAWMP goals (2,394,926 * 0.80).

West Coast of Mexico / Baja Peninsula Mid-winter waterfowl surveys in the 1970’s indicated that about 16% of all Northern Pintails in the Pacific Flyway wintered along the west coast of Mexico, with less than 1% wintering along the Baja Peninsula. Mid-winter surveys of ducks in western Mexico have largely been discontinued though surveys were conducted in 1997 and 2000. During these two years Northern Pintail counts on Mexico’s west coast averaged 109,000 birds (10% of the Pacific Flyway total), down from an average of 600,000 in the 1970’s. Northern Pintail numbers on the Baja Peninsula averaged less than 1,500 birds during the 1997 and 2000 surveys. The apparent decline in pintail numbers on Mexico’s west coast may be related to loss of the local rice industry (M. Miller pers. com.). Northern Pintail migration corridors described by Bellrose (1980) indicate that the majority of Northern Pintails wintering on Mexico’s west coast migrate east of SONEC in spring. Pintails that were fitted with satellite transmitters in New Mexico and which later migrated

4.10

Figure 4 J  oint Ventures that contribute to spring Northern Pintail populations in southern Oregon and northeastern California (SONEC) region.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Table 3 W  intering areas that supply SONEC region with spring migrating Northern Pintails. PINTAIL POPULATION OBJECTIVE

WINTERING AREA Central Valley Non-Central Valley Counties SONEC Total

PINTAILS SUPPLIED TO SONEC

2,394,926 b a

537,013

1,915,941

b

429,610

72,409

72,409

3,004,348

2,417,960

a

C alifornia counties outside the boundaries of the Central Valley Joint Venture excluding counties in SONEC.

b

E ighty-percent of all pintails wintering in these areas are assumed to migrate through SONEC in spring.

California Counties outside the CVJV (excluding CA counties in SONEC) California contains 58 counties; 26 within the CVJV boundary, 4 within SONEC. The remaining 28 counties fall within the boundaries of the Pacific Coast, Intermountain West, San Francisco Bay, and Sonoran Joint Ventures (Fig. 4). The combined mid-winter population objective for Northern Pintails in these 28 counties stepped down from the NAWMP is 537,013 (Table 3). Although these counties lie outside the Central Valley we assumed that a similar percentage wintering in these counties use SONEC in spring. Thus, these 28 counties would contribute 429,610 Northern Pintails to SONEC when continental population of Northern Pintail is at NAWMP goals (537,013 * 0.80). Many of these counties border the Pacific coast and some of these birds may use a coastal migration route that takes them west of SONEC (Miller et al. 2005). However, the total population objective for Northern Pintails in these coastal counties is less than 140,000 birds. California and Oregon counties within SONEC SONEC includes seven counties, all of which occur in the IWJV (Fig. 4), with a NAWMP mid-winter population objective of 236,961 Northern Pintails (Koneff 2003). Long-term surveys of waterfowl in SONEC from fall through spring indicate that peak waterfowl numbers occur outside the mid-winter period (Gilmer et al. 2004). This contrasts with the Central Valley and other parts of California where peak waterfowl numbers occur during mid-winter. The mid-winter Northern Pintail population objective for SONEC is likely a significant overestimate. NAWMP mid-winter objectives for areas that experience peak bird abundance in fall or spring are likely associated with a high degree of sampling error (Petrie et al. 2011). Counts of Northern Pintails in sub-regions of the Pacific Flyway

4.11

Mid-winter Waterfowl Survey that corresponds to SONEC (OR 69-3 & CA 14-2) averaged only 52,000 birds during the 1970’s. Even if a visibility correction factor is applied to these counts they are well below Koneff ’s (2003) midwinter pintail population objective for SONEC counties. The JV established a mid-winter pintail population objective of 72,409 birds for SONEC counties. This is equivalent to the mean mid-winter count of Northern Pintails in these counties during the 1970’s (52,093) adjusted for visibility bias in aerial surveys of wintering ducks (Pearse et al. 2008). Mid-winter counts of in SONEC during the 1990’s averaged 44,139 Northern Pintails, and more recent counts by Fleskes and Yee (2007) averaged 38,957 in early January (both uncorrected for visibility bias). It was assumed that 100% of the Northern Pintails present in SONEC during mid-winter also occur there in spring. In summary, the IWJV estimate that 2,417,960 Northern Pintails use SONEC in spring when the continental population is at the NAWMP goal (Table 3).

Daily Northern Pintail Population Objectives for Spring Northern Pintail migration through SONEC is staggered from early February to early May, with peak numbers occurring in mid-March (Miller et al. 2005, Fleskes and Yee 2007). Establishing time-specific population objectives across this 3-month period can help deliver conservation programs that are well timed to migration events. Fleskes and Yee (2007) used aerial survey data to index changes in SONEC Northern Pintail abundance between early January and early May in 2002 and 2003. These surveys were used to partition use-days into discreet time intervals and convert those use-days into daily population objectives as described below. Fleskes and Yee (2007) obtained Northern Pintail counts in SONEC for 5 January, 21 February, 13 March, 16 April, 30 March, and 3 May. The JV partitioned the spring migration period into five time intervals that were similar in length and which were bracketed by these survey dates: a) 6 – 21 February, b) 22 February – 13 March, c) 14 March – 30 March, d) 31 March – 16 April, and e) 17 April 17 – 3 May. Northern Pintails that winter south of SONEC do not begin migration into SONEC until the first week of February (Miller et al. 2005), so we assumed that Northern Pintail numbers remained constant from 5 January to 5 February and that the number of birds present in SONEC on 5 February was equal to the number observed by Fleskes and Yee (2007) on 5 January. Northern Pintail counts on 5 January for 2002 and 2003

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) averaged 38,957 birds (Fleskes and Yee 2007). For the period 6 February – 21 February we assumed Northern Pintail numbers increased linearly from 38,957 on 5 February to 440,056 on 21 February 21 (440,056 was the number observed on the February 21 survey date). This process was repeated for the remaining time intervals. To calculate Northern Pintail use-days in each time interval, daily estimates of Northern Pintail numbers were based on the assumption that their numbers increased or decreased in a linear manner between survey dates. Use-days in each time interval was then divided by total Northern Pintail use-days for all intervals. For example, 16.5% of all Northern Pintail use-days occurred in the 5–21 February time interval. The estimated number of use-days that would occur when Northern Pintails are at the NAWMP goal was used to calculate daily population objectives. During spring migration Northern Pintails spend an average of 21.5 days in SONEC (Miller et. al. 2005). The number of Northern Pintails using SONEC when they are at the NAWMP goal is estimated to be 2,417,960 birds (Table 3). Thus, an estimated 51,986,140 Northern Pintail use-days occur in SONEC when the NAWMP goal is met (2,417,960 * 21.5). For each time interval this use-day number was multiplied by the fraction of total use-days estimated for that interval. For example 16.5 % of all Northern Pintail use-days occur in the 5–21 February interval which results in an estimated 8,577,713 use-days for this interval (0.165 * 51,986,140). To convert these use-days into daily population objectives we calculated average number of birds per day that corresponded to use-day totals for an interval. The 5–21 February interval spans 17 days. As a result, the average number of birds per day in this interval equals 504,571 (8,577,713 / 17). The average number of birds per day was equal the mid-point daily population objective for that interval and birds were assumed to increase or decrease in a linear manner in each time interval (Fig. 5).

Figure 5 D  aily population abundance objectives for Northern Pintails in the SONEC region during spring migration. 4.12

SONEC Subregion Northern Pintail Population Objectives The SONEC planning unit has been divided into several subregions to facilitate conservation planning (Fig. 3). Daily Northern Pintail population objectives should be distributed among subregions in a way that reflects bird use of these basins in both space and time. Fleskes and Yee (2007) reported aerial survey results by subregion as well as for the entire SONEC region for 5 January, 21 February, 13 March, 16 April, 30 March, and 3 May. These surveys provided an estimate of Northern Pintail distribution among subregions throughout the spring migration period. To establish daily population objectives for each subregion the same time intervals as Fleskes and Yee (2007) were adopted and it was assumed the fraction of total SONEC Northern Pintails in a subregion increased or decreased linearly in each time interval. For example 17% of all SONEC Northern Pintails were observed in the Upper Klamath subregion during the 21 February survey, and 14% were observed in this subregion during the 13 March survey. The fraction of total SONEC pintails in the Upper Klamath subregion were assumed to exhibit a linear decline within the 22 February–13 March interval from about 17% to 14% of all birds. The fraction of total SONEC Northern Pintails in a subregion was multiplied by the overall SONEC Northern Pintail population objective for that date to establish a daily Northern Pintail population objective (Fig. 5). For example, 15.6% of all SONEC Northern Pintails are estimated to be in the Upper Klamath subregion on March 3 (the mid-point of the 22 February–13 March interval), while the 3 March objective for SONEC is 1,108,727. Thus, the 3 March Northern Pintail objective for the Upper Klamath subregion is 172,961 birds (0.156 * 1,108,727).

Spring Population Objectives for Other Dabbling Duck Species Spring population objectives were also established for five other dabbling duck species: American Wigeon, Mallard, Green-winged Teal, Northern Shoveler, and Gadwall. Unfortunately, data to establish population objectives for spring diving ducks were insufficient. It was assumed most dabbling ducks that migrate through SONEC originate from one of three wintering areas; 1) the Central Valley, 2) California counties outside the Central Valley, excluding California counties in SONEC, and 3) Oregon and California counties within SONEC (Fig. 4). Mid-winter dabbling duck population objectives stepped down from the NAWMP are available for each of these areas (Koneff 2003). These mid-winter population objectives for the first two wintering areas were adopted assuming that 80% of these birds use SONEC in spring as

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) estimated for Northern Pintails (Miller et al. 2005). For Oregon and California counties in SONEC, mid-winter surveys were relied upon to establish winter population objectives as described for Northern Pintails and it was assuming that 100% of these birds use SONEC in spring (Table 4). The only exception was Mallard. For all species except Mallards Fleskes and Yee (2007) documented large increases in bird numbers from early February through mid to late March as birds left their California wintering grounds and migrated into SONEC. In contrast, Mallard numbers in SONEC declined after early February. This is consistent with other work that suggests most Central Valley Mallards are year-round residents (Central Valley Joint Venture 2006). Population objectives for Mallards were established by using direct counts of Mallards that were adjusted for visibility bias and un-surveyed areas (Fleskes and Yee 2007). Table 4 N  umber of dabbling ducks that migrate through SONEC in spring when dabbling duck populations are at NAWMP goals. SPECIES

Northern Pintail

2,418,000

American Wigeon

1,140,000

Northern Shoveler

613,000

Green-Winged Teal

520,000

Gadwall

111,000

Mallard Total a

NUMBER OF BIRDS USING SONEC

a

Spring Population Objectives for Geese and Swans Many North American goose and swan populations have significantly increased or undergone major changes in wintering distribution since the 1970’s. As a result, Joint Ventures are advised to use more recent information when establishing population objectives for geese and swans (M. Koneff pers. comm.). Snow geese, Ross’s geese, White-fronted geese, Canada geese, and Tundra Swan all use SONEC in spring. Fleskes and Yee (2007) surveyed goose and swan populations in SONEC on 21 February, 13 March, 30 March 16 April, and 3 May in both 2002 and 2003. For both geese and swans the spring migration period was partitioned into five intervals of similar length; 1) 9 February – 2 March, 2) 3 March – 21 March, 3) 22 March – 7 April, 4) 8 April – 24 April, 5) 25 April – 11 May. Each survey date corresponded to the mid-point of an interval (e.g., the 21 February survey serves as the mid-point for the 9 February – 2 March interval). The number of birds observed during these mid-point surveys served as population objective for that interval (Table 5). Table 5 S  pring population objectives by time interval for geese and swans in SONEC.

66,000 4,868,000

 allard numbers in Table 4 are an estimate of the peak population size M occurring in SONEC, not an estimate of the total number of mallards using SONEC in spring. As a result, this number should be considered a minimum estimate of population size.

Daily population objectives for each of the five dabbling duck species were established between 5 February and 3 May using the same methods described for Northern Pintails and assuming the same duration of stay in SONEC (i.e. 21.5 days). Daily population objectives for each dabbling duck species were distributed among the seven SONEC subregions also using the same methods described for Northern Pintail. Mallard, Northern Pintail, and American Wigeon have all been designated as Birds of Management Concern by the USFWS and are further classified as Game Birds Below Desired Condition. The IWJV recognizes Northern Pintail, Mallard, and American Wigeon as priority dabbling duck species based on their USFWS status and their contribution to SONEC fall, winter, and spring dabbling duck population.

4.13

a b

CANADA GEESE

WHITE GEESEB

INTERVAL

GWFGA

SWANS

TOTAL

Feb 9Mar 2

150,741

20,340

179,216

67,902

418,199

Mar 3Mar 21

183,964

11,616

280,774

25,652

502,006

Mar 22Apr 7

179,250

11,547

255,701

3,328

449,826

Apr 8Apr 24

163,589

8,135

105,848

15

277,587

Apr 25May11

57,774

7,066

16,710

16

81,566

Greater White-Fronted Geese Includes Lesser Snow Geese and Ross Geese

Limiting Factors/Species–Habitat Models Limiting factors and species-habitat models used to evaluate population carrying capacity are described previously in this chapter under the “Structure of the Nonbreeding Waterfowl Plan” section.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Conservation Design Landscape Characterization and Assessment: SONEC Fall and Winter Most waterfowl in SONEC rely on public lands to meet their food energy needs. Although SONEC contains several publicly managed areas, Tule Lake and Lower Klamath NWR are especially important to waterfowl. These refuges are managed by the USFWS as part of the Klamath Basin NWR Complex. The Klamath Basin is recognized as a region of continental significance to North American waterfowl populations (NAWMP Plan Committee 2004). Conservation and management of waterfowl habitats on both refuges depend heavily on water supplies, and increasing competition within the Klamath Basin for water requires the USFWS be able to articulate and defend habitat requirements and water needs. Both refuges recently underwent intensive planning efforts focused on three main objectives; 1) evaluate current refuge habitat management practices relative to waterfowl food energy needs; 2) identify foraging habitat deficiencies that may exist; and 3) evaluate potential management alternatives for meeting waterfowl food energy needs (Dugger et al. 2008). Planning for fall and winter waterfowl in SONEC is largely synonymous with public land planning, so key elements of the Tule Lake and Lower Klamath plans are included here. Future updates to the IWJV implementation plan should include summaries of other public land plans as they become available and will reflect the JV’s commitment to help agencies meet their goals for waterfowl on public habitats. The Tule Lake and Lower Klamath plans were based on SHC principles and relied on the TRUEMET model. The carrying capacity analyses that addressed the three main objectives of the refuge plans are described below. Further details are provided in Dugger et al. (2008).

Model Inputs Time Periods Being Modeled The fall-winter period in SONEC is defined as September 1–January 31. Waterfowl food energy needs and habitat food energy supplies were modeled at two-week intervals within this five-month period for each refuges.

4.14

Population Objectives by Time Periods Population objectives for all time periods in fall-winter were established for dabbling ducks, diving ducks, geese, and swans for both Tule Lake (Table 1), and Lower Klamath (Table 2). Daily Energy Requirements of a Single Bird Waterfowl requirements were modeled by foraging guild (e.g., diving vs. dabbling ducks). A weighted body mass was calculated for each guild because species vary in size. We assumed a balanced sex ratio for all species. Body mass values for all duck species and for swans was obtained from Bellrose (1980). A weighted mean for each two week period was calculated to account for changes in species composition of a foraging guild as indicated by aerial surveys (Gilmer et al. 2004). Body mass was considered constant across time for dabblers, divers, Western Canada geese, and swans, but was allowed to vary for Ross’ Geese, Lesser Snow Geese, Greater Whitefronted Geese, and Cackling geese based on data from Ely and Raveling (1989), McLandress (unpublished data), and Raveling (1979). Habitat Availability and Biomass and Nutritional Quality of Foods Six habitat types including harvested and un-harvested grain crops, harvested potato fields, alfalfa/hay, and seasonal and permanent wetlands are available on the refuges (Table 6). Seasonal wetlands are typically flooded in fall or winter and dewatered in spring or early summer; permanent wetlands are flooded year round. Seasonal wetlands were further divided into early and late successional habitats to reflect differences in seed production and permanent wetlands were divided into area dominated by SAV or robust emergent vegetation (primarily hardstem bulrush and cattail). Food production in permanent wetland areas dominated by robust emergents was set at 0.0 because the dense growth and tall, robust stature of these plants make foods in these habitats generally unavailable to waterfowl. Seeds that might have been produced by this plant community that dispersed into other habitats would have been included in food abundance estimates. Refuge personnel provided information on existing habitats at Tule Lake and Lower Klamath for 2005. Waterfowl that rely on the refuges were assumed to exploit both agricultural and wetland habitats to meet food energy needs.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) possible (Table 8). When the TME value of a food was unknown, value for a similar food type was used. When a comparable species was not available, TME was estimated using a regression relationship between TME value and the proximate composition of a food (Petrie et al. 1998).

Table 6 H  abitat composition (acres) at Tule Lake and Lower Klamath National Wildlife Refuges during 2005. REFUGE

HABITAT TYPE

LOWER KLAMATH

TULE LAKE

Table 7 F  ood densities from agricultural and wetland habitats at Lower Klamath and Tule Lake NWRs.

SEASONAL WETLANDS Early Succession Late Succession

4,834

0

11,280

155

REFUGE

PERMANENT WETLANDS Submerged Aquatic Veg.

7,355

11,539

Robust Emergent Veg.

1,839

3,030

Harvested Grains

6,534

8,471

Standing Grains

1,057

249

0

2,703

2,018

3,405

34,917

29,552

Harvested Potatoes Green Browse Total Habitat

Availability refers to the ability of waterfowl to access foods produced in a habitat. Availability varies with flooding conditions and crop harvest practices and can vary among guilds for a specific habitat type. For example, Mallard and Northern Pintail commonly feed in dry agricultural fields or wetland basins lacking surface water, but many species of ducks (e.g., diving ducks) do not feed unless surface water is present. Information provided by refuge staff was used to determine when and how quickly foods in each habitat type became available. Foods in permanently flooded wetlands and unharvested grain fields were considered 100% available at the beginning of fall (September 1). Seasonal wetlands began flooding during mid-September and filled at a constant rate until January 1 when all were filled. It was assumed grain crops are harvested and available by September 15. Potatoes were considered available starting October 1 because harvesting is initiated about October 1 and proceeds at a steady rate until all fields are harvested by about November 1. Wetland food densities were determined by sampling refuge habitats (Table 7). True metabolizable energy of refuge foods was obtained from published sources where

4.15

TLNWR (lbs/acre)

HABITAT TYPE Harvested Potatoes a

437

176

176

77

77

157

156

19

42

41.9

56.0

Barley

4,960

4,960

Oats

4,464

Wheat

5,952

5,675

4,960

Seeds-Early Succession Seasonal Wetlands

875

875

Seeds-Late Succession Seasonal Wetlands

489

489

9

9

Roots / Tubers Permanent Wetlands

49.4

218

Leafy Vegetation Permanent Wetlands

121.7

214

Green Forage (Pasture) HARVESTED GRAIN

a

a

Barley Oats Wheat Weighted Mean UNHARVESTED GRAIN

b

c

Weighted Mean WETLANDS

d

Spring Invertebrates All Wetlands

a b

c

d

LKNWR (lbs/acre)

From Kapantais et al. 2003. M ean value that reflects the proportional contribution of each crop type to the category total. H arry Carlson, University of California, Research and Extension Office, Tule Lake, California. Dusser et al. 2008.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC)

Photo by USF WS

Table 8 T  rue metabolizable energy (TME) of waterfowl foods at Tule Lake and Lower Klamath NWR. Adapted from Dugger et al. (2008) Table 4-3. TME VALUE (kcal/g)

FOOD TYPE OR CATEGORY Grains 1

3.0

Potatoes 2

4.0

Alfalfa Pasture 3

2.4

Seasonal Wetland Seeds (early succession) Seasonal Wetland Seeds (late succession) Leafy Vegetation

1 2 3 4

5 6

3

4

4

2.4 1.6 2.0

Roots / Tubers 5

2.5

Aquatic invertebrates 6

2.5

From Sugden (1971) based on proximate composition (Petrie et al. 1998). from Petrie et al. (1998) T hese metabolizable energy estimates were combined with published TME values of other moist-soil seed resources to gene rate an average TME value for seeds in early and late succession seasonal wetlands (Checkett 2002). based on foods of similar proximate composition from Purol (1975)

4.16

Carrying capacity analyses conducted at large scales (e.g., Joint Venture or ecoregion) usually assume that waterfowl meet all food energy needs within the planning area. However, at smaller scales such as refuges this is unlikely as some species consume foods outside the refuge boundary. Information from the published literature and observations of refuge staff were used to determine what percentage of each guilds daily energy needs are met on site and the habitats and food types each guild likely used to satisfy their daily energy needs (Table 9). Diving ducks and swans were assumed to satisfy 100% of their energy needs by foraging on the tubers of submerged aquatic vegetation. Although the diet of diving ducks differs, this constraint was felt to be appropriate as Canvasback was the most common species in the diver guild. Geese were assumed to forage on harvested and unharvested grain crops, (regardless of flooding status), harvested potatoes, and pasture. Dabbling ducks were assumed to feed on seeds and invertebrates in seasonal wetlands and on harvested and unharvested, flooded or unflooded, grain crops (Table 9). The extent to which each guild met their energy needs on the refuges was assumed to vary. Diving ducks and swans were allowed to meet 100% of their needs on refuge for every model simulation, while we reduced this figure to 75% for dabbling ducks and geese.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Table 9 F  ood types used by waterfowl guilds to meet daily energy demands on Lower Klamath and Tule Lake. Adapted from Dugger et al. (2008) Table 4-4.

GUILD

STANDING GRAIN

HARVESTED GRAIN

Dabbling Ducks

X

X

HARVESTED POTATOES

ALFALFA PASTURE

SEASONAL WETLAND SEEDS

PERMANENT WETLAND LEAFY VEGETATION

PERMANENT WETLAND ROOTS AND TUBERS

X

Diving Ducks

X

Dabbling Ducks Geese

X

X

X

X

Swans

X

Coots

X

Model Results Refuge habitat management practices relative to waterfowl food-energy needs Current habitats at Lower Klamath provided sufficient food-energy to meet population objectives for swans and diving ducks (Fig. 6) and dabbling ducks (Fig. 7) in fall-winter and through spring. However, Lower Klamath could not support goose population at objective levels, being exhausted prior to the March 1 interval, 6 weeks before the end of spring (Fig. 8). At Tule Lake, food resources were adequate to meet the energy needs of diving ducks and swans (Fig. 9), but were insufficient to meet the needs of dabbling ducks (Fig.10), and geese (Fig. 11). Dabbler foods were exhausted early in the fall, well before traditional peak migration in November. Goose needs were met through most of fall and winter but not spring.

Supply

Figure 7 P  opulation energy demand versus food energy supplies for dabbling ducks at Lower Klamath National Wildlife Refuge (LKNWR) relative to refuge population objectives.

Demand

Demand

Supply

Supply

Figure 6 P  opulation energy demand versus food energy supplies for diving ducks and swans at Lower Klamath National Wildlife Refuge (LKNWR) relative to refuge population objectives.

4.17

Demand

Figure 8 P  opulation energy demand versus food energy supplies for geese at Lower Klamath National Wildlife Refuge (LKNWR) relative to refuge population objectives.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC)

Demand

Demand

Supply

Supply

Figure 9 P  opulation energy demand versus food energy supplies for diving ducks and swans at Tule Lake National Wildlife Refuge relative to refuge population objectives.

Demand

Figure 11 P opulation energy demand versus food energy supplies for geese at Tule Lake National Wildlife Refuge relative to refuge population objectives.

LOWER KLAMATH

Supply

1970’s 1990’s

Figure 10 P opulation energy demand versus food energy supplies for dabbling ducks at Tule Lake National Wildlife Refuge relative to refuge population objectives.

Carrying capacity results were consistent with waterfowl population differences on both refuges during the 1970s versus 1990s. Dabbling duck numbers at Tule Lake have significantly declined since the 1970’s (Fig. 2). During this time the amount of standing grain grown for waterfowl was reduced from 2,000 to 250 acres. The decline in dabbling duck abundance from the 1970s to the 1990s is consistent with this loss of standing grain and with evaluations of carrying capacity at Tule Lake (Fig. 10; Dugger et al 2008)). In contrast, dabbling duck counts at Lower Klamath have remained stable or increased from the 1970’s (Fig. 12) and are consistent with model results for the refuge (Fig. 7).

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TULE LAKE 1970’s 1990’s

Figure 12 M ean aerial survey counts of dabbling ducks by date at Lower Klamath and Tule Lake NWR’s in 1970–1979 and 1990–1999.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Evaluation of potential management alternatives for meeting waterfowl food energy needs Dugger et al. (2008) evaluated several management alternatives for meeting waterfowl food energy needs at Tule Lake and Lower Klamath. The JV included one management alternative for each refuge to demonstrate the utility of this planning approach. Lower Klamath: the â&#x20AC;&#x153;Big Pondâ&#x20AC;? scenario The evaluation of current habitat conditions for Lower Klamath assumed that flooding of seasonal wetlands began in early September and progressed until all wetlands were full by January 1, the pattern representing historic management hydroperiod. However, chronic water shortages during summer and fall during the last 15 years have made achieving this flooding schedule increasingly difficult. Consequently, managers at Lower Klamath are exploring ways to capture water during winter and early spring, a time when water is typically in abundance. One alternative, called the Big Pond Scenario, would create a 13,000 acre unit on the southern half of Lower Klamath, where management would focus on capturing water in winter and spring to fill the unit and then allow levels to gradually recede during the summer and fall, essentially mimicking conditions on historic Lower Klamath Lake. This would require approximately 50,000 to 70,000 acre-feet of water to fill the unit, and water depths would range from seven feet at deepest part to inches at the margins. Preliminary hydrologic analysis indicates sufficient water is available in most years to fill the Big Pond. Even with no water deliveries in summer, the area would support large numbers of colonial nesting waterbirds as well as molting and breeding waterfowl. Approximately half of the surface area would remain flooded during fall migration. Similar management on smaller areas at Lower Klamath has provided impressive habitat response and high use by waterbirds. Dugger et al. (2008) used TRUEMET to understand the consequences of the Big Pond Scenario to foraging waterfowl by altering the composition of wetland habitat types on the refuge. The first step was to assign the 13,000 acres associated with the scenario to wetland categories. The predicted hydroperiod assumes that half (6,500 acres) of area draws down naturally between May and November as a result of evapotranspiration. Thus, half of the area was classified as a seasonal wetland and the remaining half as permanent wetland. Half of the seasonal wetland

4.19

component (3,250 acres) would occur at elevations high enough for moist soil plants to germinate and mature (i.e., water would draw down early enough). For these acres, a food density equal to other Lower Klamath seasonal wetland habitats was used; however, because low lake levels will keep these areas dry in fall, these acres would only be available to foraging waterfowl beginning 1 March when flooding begins. It was assumed that flooding progressed in a linear fashion from 1 March until the area is full on 15 April. For the remaining 3,250 acres of the seasonal wetland portion of the Big Pond waterfowl foraging value was set to zero. The number of acres dedicated to agriculture on the refuge was not altered so all habitat distribution changes came soley from existing wetlands acres. The total wetland acreage on Lower Klamath is 25,308 acres. After allocating 13,000 to the Big Pond Unit, the remaining acreage was allocated to seasonal wetlands. The final allocation resulted in little change in seasonal wetland acres but a significant decline in permanent wetland acres (Table 10). Table 10 A cres dedicated to wetland habitat types under current conditions and under the Big Pond Scenario at Lower Klamath NWR, California. WETLAND TYPE Permanent wetland

BIG POND SCENARIO

9,194

6,500

Seasonal wetland

16,114

15,558

No feeding value a

0

3,250

25,308

25,308

TOTAL a

CURRENT

 he number of acres in the Big Pond Unit that will dry during summer but T not produce moist soil plants

Dugger et al. (2008) used TRUEMET to simulate how the Big Pond Scenario influenced energy supplies for dabblers, divers and swans. Geese were not modeled because agricultural habitats were not influenced and geese obtain their energy from the agricultural crops. Results suggest that it may represent a reasonable alternative strategy for meeting waterfowl needs if long-term solutions are not found to alleviate water shortages during summer and early fall. Dabbling duck food resources were adequate under this management alternative (Fig. 13), as were the food energy needs of diving ducks and swans (Fig. 14).

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC)

Demand Supply

Figure 13 P opulation energy demand versus food energy supplies for dabbling ducks at Lower Klamath NWR under habitat conditions outlined in the Big Pond Scenario.

Dabbling duck and goose populations at Tule Lake have substantially declined since the 1970s (Fig. 12), as has the acreage of standing grains. Dugger et al. (2008) modeled the management alternative of increasing standing grain acreage to 1970s levels (2,000 acres) to determine if dabbling duck and goose population objectives could be supported at population objective levels (Table 1). Increasing unharvested grains from 250 to 2,000 acres would allow Tule Lake to meets the foraging needs of dabbling ducks (Fig. 15) and geese (Fig. 16). From a purely energetic standpoint, the decline in dabbling duck and goose populations since the 1970s on Tule Lake is consistent with the reduction in unharvested grains.

Demand Supply

Demand Supply

Figure 14 P opulation energy demand versus food energy supplies for diving ducks and swans at Lower Klamath National Wildlife Refuge under habitat conditions outlined in the Big Pond Scenario.

Figure 15 P opulation energy demand versus food energy supplies for dabbling ducks at Tule Lake National Wildlife Refuge with standing grain acreage restored to 1970s level.

Tule Lake: Increased Standing Grain Tule Lake NWR staff farmed approximately 2,000 acres of small grains during the 1970s to provide food for waterfowl and depredation relief to farmers on private lands. This program was discontinued in the 1980s in favor of a program using cooperating farmers. Under this program, the farmer provided all costs of establishing a crop, harvested two-thirds of the crop, and left one-third standing for waterfowl consumption. This was deemed an acceptable change because populations of waterfowl in the Pacific Flyway (particularly geese) in the 1980s were lower than previous decades, and much of the standing grain was not used. The cooperative farming program was further reduced in the 1990s and availablity of unharvested grain declined from about 2,000 acres in the 1970s to 250 acres by 2005.

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Figure 16 P opulation energy demand versus food energy supplies for geese at Tule Lake National Wildlife Refuge with standing grain acreage restored to 1970s level.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Spring Although waterfowl that use SONEC in fall and winter rely mostly on public habitats to meet their food energy needs, private lands play a critical role during spring migration. Many of these private lands are former seasonal wetlands that are now devoted to forage production for cattle. Ranchers flood irrigate these lands during spring to increase soil moisture and they are heavily used by spring migrating birds (Fleskes and Yee 2007) . A more detailed description of these flood irrigated habitats can be found in the Biological Planning section . Virtually all flood-irrigated wetland habitat in SONEC is unprotected. To inform protection objectives for this habitat type two carrying capacity analyses were done for each subregion; 1) the overall capacity of flood-irrigated habitats to meet food energy needs of dabbling ducks during spring migration in each of SONEC’s subregions, and 2) the amount of flood-irrigated habitat needed to meet 100% of dabbling duck needs during spring. Model inputs and results of these analyses are specific to dabbling duck populations because diving ducks and geese are seldom associated with flood irrigated habitats.

Model Inputs Time Periods being Modeled The spring period in SONEC is defined as early February through early May and was divided into eight time periods of similar length; 1) 6 Feb - 16 Feb, 2) 17 Feb - 27 Feb, 3) 28 Feb – 10 Mar, 4) 11 Mar – 21 Mar, 5) 22 Mar – 1 Apr, 6) 2 Apr – 12 Apr, 7) 13 Apr – 23 Apr, and 8) 24 Apr – 4 May. Dabbling duck food energy needs and food energy supplies were modeled for each of these intervals.

Habitat Availability and Biomass and Nutritional Quality of Foods The amount and distribution of flood-irrigated habitat in SONEC was determined using LandSat Thematic (TM) satellite imagery from February and April 2002 and from February and May 2003 (Fleskes and Gregory 2010). The amount of flood-irrigated habitat varied within and among years, with habitat generally increasing from February to May as temperatures warmed and land owners diverted water onto hay and pasture lands. For each SONEC subregion, the peak estimate of flood irrigated habitat in 2002 and 2003 was averaged for use in the TRUEMET model. These peak estimates mostly corresponded to the April and May satellite images. Average peak amounts of flood irrigated habitat by subregion are presented in Table 11. Food sampling of flood-irrigated habitats in spring of 2008 and 2009 indicated that these habitats provide an average of 152 lbs / acre of seeds that are consumed by waterfowl (J. Fleskes, U.S. Geological Survey, unpublished data). It was assumed that the giving-up density or foraging threshold for flood-irrigated habitats was 30 lbs / acre, which reduced the food density estimate in the TRUEMET model to 122 lbs / acre (Naylor 2002). Finally, seed resources in these habitats were assumed to provide a TME of 2.5 kcal/g (Checkett et al. 2002). Table 11 T he amount of existing flood-irrigated habitat in each SONEC subregion and the amount of flood irrigated habitat needed to meet 100% of dabbling duck needs.

SONEC SUB-REGION

Population Objectives by Time Period Total dabbling duck population abundance objectives for SONEC during spring equate to approximately 4.9 million birds, with Northern Pintails comprising about 50% of the total (Table 4). A description of how these population objectives were established can be found in the SONEC Biological Planning Section.

EXISTING FLOODIRRIGATED HABITAT (ACRES)

FLOOD-IRRIGATED HABITAT NEEDED TO MEET 100% OF DABBLING DUCK NEEDS (ACRES)

Modoc Plateau

13,000

18,000

Malheur

15,300

7,000

NE California

13,500

13,000

Upper Klamath

18,800

23,000

Daily Bird Energy Requirements

Summer Lake

4,100

11,000

To estimate the daily energy needs of dabbling ducks during spring, a weighted body mass was calculated for each time period to account for changes in species composition of dabbling duck populations during spring. Average body mass of adult males and females was obtained for all species from Bellrose (1980), and a balanced sex ratio was assumed.

Warner Valley

7,500

14,000

Lower Klamath

7,100

Not Determined

79,300

86,000 a

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Total

This estimate excludes that portion of the SONEC dabbling duck population that relies on the Lower Klamath Subregion. a

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Model Results The capacity of flood-irrigated lands to meet the food energy needs of dabbling ducks between February 6 and May 4 (spring) was evaluated for each subregion. The amount of flood irrigated habitat needed to meet 100% of dabbling duck needs during this period was also estimated. In some basins flood irrigated lands can only meet a fraction of duck energy needs during spring, while in other basins these habitats can provide in excess of 100% of bird needs. However, dabbling ducks do not rely exclusively on flood-irrigated habitats to meet their food energy requirements. Managed public lands and to a lesser extent managed private lands in SONEC can also provide important food resources. Establishing protection objectives for flood-irrigated lands requires a decision about what role publicly and privately managed wetlands should play in meeting the needs of spring migrating waterfowl. For example, if managed wetlands in the Warner Valley subregion can provide 50% of dabbling duck needs then the presumption is flood-irrigated habitats must provide the rest. However, estimating the capacity of flood-irrigated lands to meet dabbling duck needs is only a first step in establishing protection objectives for these habitats. Modoc Plateau Subregion There are an estimated 13,000 acres of flood-irrigated wetlands in the Modoc subregion. These existing habitats can meet the food energy needs of target dabbling duck populations into the third week of March (Fig. 17). An estimated 18,000 acres of flood irrigated lands would be needed to meet 100% of dabbling duck needs for the entire spring migration period (Table 11).

Figure 17 F ood energy (kilocalories) provided by floodirrigated habitats (red) vs. dabbling duck energy demand (black) during spring in the Modoc subregion of SONEC.

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Malheur Subregion An estimated 15,300 acres of flood-irrigated habitat exists in the Malheur subregion. These existing habitats can meet the food energy needs of target dabbling duck populations for the entire spring migration period (Fig. 18). In actuality, it was estimated that only 7,000 acres of flood irrigated lands would be needed to meet 100% of dabbling duck needs for the entire spring migration period (Table 11).

Figure 18 F ood energy (red) provided by flood-irrigated habitats vs. dabbling duck energy demand (black) during spring in the Malheur subregion of SONEC.

Northeast California Subregion An estimated 13,500 acres of flood-irrigated wetlands occur in the Northeast California subregion, and can meet the food energy needs of target dabbling duck populations for the entire spring migration period (Fig. 19). In actuality, the JV estimated that only 13,000 acres of floodirrigated lands would be needed to meet 100% of dabbling duck needs for the entire spring migration period (Table 11).

Figure 19 F ood energy (kilocalories) provided by floodirrigated habitats (red) vs. dabbling duck energy demand (black) during spring in the NE California subregion of SONEC.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) Upper Klamath Subregion

Warner Valley Sub-Region

There are an estimated 18,800 acres of flood-irrigated wetlands in the Upper Klamath subregion. These existing habitats can meet the food energy needs of target dabbling duck populations into the first week of April (Fig. 20). An estimated 23,000 acres of flood irrigated lands would be needed to meet 100% of dabbling duck needs for the entire spring migration period (Table 11).

There are an estimated 7,500 acres of flood-irrigated wetlands in the Warner Valley subregion. These existing habitats can meet the food energy needs of target dabbling duck populations through mid-March (Fig. 22). An estimated 11,000 acres of flood irrigated lands would be needed to meet 100% of dabbling duck needs for the entire spring migration period (Table 11).

Figure 20 F ood energy (kilocalories) provided by floodirrigated habitats (red) vs. dabbling duck energy demand (black) during spring in the Upper Klamath subregion of SONEC.

Figure 22 F ood energy (kilocalories) provided by floodirrigated habitats (red) vs. dabbling duck energy demand (black) during spring in the Warner Valley subregion of SONEC.

Summer Lake Subregion

Lower Klamath Subregion

An estimated 4,100 acres of flood-irrigated wetlands exisist in the Summer Lake subregion and can meet food energy needs of target dabbling duck populations through early March (Fig. 21). An estimated 14,000 acres of floodirrigated lands would be needed to meet 100% of dabbling duck needs for the entire spring migration period (Table 11).

There are an estimated 7,100 acres of flood-irrigated wetlands in the Lower Klamath subregion (Table 11). These existing habitats can only meet the food energy needs of target dabbling duck populations through early February (Fig. 23). The Lower Klamath subregion contains the Tule Lake and Lower Klamath National Wildlife Refuges, both of which have traditionally supported large numbers of spring migrating waterfowl. As a result, dabbling duck population objectives for the Lower Klamath subregion far surpass that of other SONEC subregions. It is anticipated that dabbling duck needs in this subregion will be largely met on refuge lands. Therefore, the amount of flood irrigated lands needed to meet 100% of dabbling duck needs was not estimated.

Figure 21 F ood energy (kilocalories) provided by floodirrigated habitats (red) vs. dabbling duck energy demand (black) during spring in the Summer Lake subregion of SONEC.

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SOUTHERN OREGON & NORTHEASTERN CALIFORNIA (SONEC) needs in the Lower Klamath subregion. Habitat objectives for flood-irrigated habitat are a function of dabbling duck food energy needs and the fraction of energy needs to be met on flood-irrigated lands. Managed public lands and managed private lands (primarily Wetland Reserve Program tracts) also provide food resources for migrating waterfowl. Table 12 provides an estimate of the amount of flood-irrigated wetlands needed in each subregion depending on assumptions regarding the role of public and privately managed habitats in meeting dabbling duck needs. Figure 23 F ood energy (kilocalories) provided by floodirrigated habitats (red) vs. dabbling duck energy demand (black) during spring in the Lower Klamath subregion of SONEC.

Habitat Objectives for SONEC: Spring Flood-irrigated Wetlands The capacity of flood-irrigated wetlands to meet the needs of target dabbling duck populations varies widely among SONEC subregions. For example flood irrigated lands in the Malheur subregion appear able to meet > 100% of dabbling duck food energy needs, while flood irrigated habitat can only provide a small portion of duck energy

Research has estimated that that over 70% of habitat use by radio-marked Northern Pintail in SONEC, excluding Lower Klamath subregion, occur on privately owned habitats during spring migration (Fleskes et al. 2013. Additionally, 50â&#x20AC;&#x201C;75% of Northern Pintail use is estimated to occur in flood-irrigated habitat within five of the seven most important SONEC subregions for spring migrating Northern Pintails (Fleskes et al. 2013). The IWJV therefore assumes that 75% of the energy demand for spring migrating dabbling ducks will be met on privately managed flood-irrigated habitats in SONEC. Consequently, the IWJV habitat objective for flood-irrigated habitat in SONEC, outside of the Lower Klamath subregion, is 64,700 acres, as needed to sustain spring-migratory dabbling ducks at NAWMP goal levels (Table 12).

 Table 12 The amount of flood-irrigated habitat (FIH) required to meet dabbling duck needs at various levels. Dabbling duck needs not met by FIH are assumed to be met by public lands or privately managed wetlands (e.g. WRP). FLOOD-IRRIGATED HABITAT (acres) REQUIRED TO MEET

EXISTING FLOODIRRIGATED HABITAT (acres)

SONEC SUBREGION

50% OF DABBLING DUCK NEEDS

25% OF DABBLING DUCK NEEDS

Modoc Plateau

13,000

13,500

9,000

4,500

Malheur

15,300

5,300

3,500

1,800

NE California

13,500

9,800

6,500

3,300

Upper Klamath

18,800

17,300

11,500

5,800

Summer Lake

4,100

8,300

5,500

2,800

Warner Valley

7,500

10,500

7,000

3,500

Lower Klamath

7,100

Not Determined

Not Determined

Not Determined

79,300

64,700

43,000

21,700

Total a a

75% OF DABBLING DUCK NEEDS

T hese estimate excludes that portion of the SONEC dabbling duck population that relies on the Lower Klamath Subregion.

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GREAT SALT LAKE

Photo by Brad Manchas

Biological Planning Spatial Planning Unit The Great Salt Lake (GSL) is among the largest wetland complexes in the western US and is internationally recognized for its importance to wetland dependent migratory birds, particularly waterfowl (Aldrich and Paul 2002, NAWMP 2004). Bellrose (1976, 1980) suggested as many as 3â&#x20AC;&#x201C;5 million waterfowl migrate through the GSL system. Although it receives only 15 inches of rainfall per year, it is surrounded by more than 470,000 acres of wetlands (Aldrich and Paul 2002). Maintained by fresh water from the Jordan, Ogden, and Bear Rivers, these wetlands provide critical waterfowl habitat in the Intermountain West. The GSL marshes are both expansive and diverse, have large areas of open water, and are rich in a variety of invertebrate and plant food resources. These features are the keystone of GSLâ&#x20AC;&#x2122;s value to migrating waterfowl. The evolution of waterfowl migrations through GSL is related to its historic importance in providing highquality habitat during fall and spring migration periods.

4.25

Waterfowl use of the GSL occurs throughout the year, but populations are highest during migration in late summer to early fall and again in spring. Ducks begin arriving from northern breeding areas as early as June and typically peak in September. Most migrating ducks arrive from the northwestern and mid-continent breeding areas in Canada and Alaska, but there is some exchange of birds with other breeding populations such as those of the Prairie Pothole Region and other Intermountain West regions. Based on banding data, ducks migrating through the GSL winter mainly in the Central Valley of California and the west coast of Mexico, but some populations migrate to the Gulf Coast, interior Mexico, and even South America. Migrants begin returning from wintering areas in February and peak in March. The spring migration period through the GSL is generally shorter and peak populations are lower than those observed in the fall (Aldrich and Paul 2002). Duck abundance is lowest during the mid-winter period but some species use saline resources of the GSL during winter (Aldrich and Paul 2002, Vest and Conover 2011).

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GREAT SALT LAKE Ducks constitute the vast majority of migrating waterfowl, but GSL also serves as a major staging area for Tundra Swans and Canada Geese. Approximately 75% of the western population of Tundra Swan migrate from Alaska breeding grounds and stage at the GSL before continuing to the Central Valley of California. Although wintering Tundra Swans feed in agricultural fields in many wintering areas, use of fields around GSL is rare. Most Canada Geese migrating through the GSL are part of the Rocky Mountain Population and it is estimated that approximately 30% migrate or winter in the GSL system. Lesser snow geese and Rossâ&#x20AC;&#x2122;s geese historically frequented the GSL in spring and fall, but recently their use has been restricted mostly to spring (Aldrich and Paul 2002). GSL is a terminal basin and historically most of the wetlands in the region were associated with the floodplain and terminal deltas of the Bear, Weber/Ogden, and Jordan Rivers (Fig. 24). However, numerous spring and seep wetlands in the system also provide important habitat for waterfowl and other wildlife. Because of its terminal nature and dependence on snow pack for river flows, the GSL system has always been a highly dynamic system in relation to waterfowl habitat. Decadal cycles of precipitation patterns were historically the largest driver of wetland and lake systems within the GSL region (Fig. 25). Increased river flows and water tables during wet cycles would create or recharge freshwater wetlands around the GSL until the saline waters of the lake itself began to increase and flood those freshwater habitats. Loss of waterfowl habitat in the GSL system due to saline flooding was likely compensated for in other Great Basin and Intermountain systems in response to regional increases in precipitation. During dry cycles, GSL elevations would recede and salinity concentrations increase within the main body of the GSL. Wetlands that had been flooded with highly saline water would be slowly flushed of those salts through natural river hydroperiods, allowing brackish and freshwater wetlands to re-establish. These dynamic conditions are directly related to high wetland productivity through space and time. The diversity and dynamic nature of wetland systems in the GSL region plays a prominent role in the observed diversity of not only waterfowl species but other wetland dependent birds.

4.26

Figure 24 Spatial planning unit for Great Salt Lake.

Figure 25 C hanges in climatic conditions can have dramatic effect on the amount, type, and distribution of wetland habitats and volume of the Great Salt Lake.

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GREAT SALT LAKE Significant man-made alterations have occurred within the GSL system over the past century, producing dramatic impacts on wetland resources and habitat for waterfowl and other wetland-dependent birds. Principally, development of water resources for agriculture, energy, industrial, and domestic use has reduced the amount and quality of fresh water reaching the lake and its marshes (Aldrich and Paul 2002, Downard 2010). The human population in the GSL region is growing rapidly, and domestic water demands will likely result in less water for upstream irrigation, GSL wetlands, and the GSL. Human development has also segmented sections of the GSL, disrupting hydrologic connectivity within the system. For example, the North Arm of the GSL is no longer connected to principal freshwater inflows which result in extreme hypersaline conditions that are unsuitable for waterfowl. Despite dramatic human alterations to the GSL system over the past century, the amount, distribution, availability, and quality of wetland resources in the GSL system remains intrinsically linked to variations in climatic conditions due to its terminal nature (Kadlec and Smith 1989, Aldrich and Paul 2002). However, increasing regional human demand for freshwater resources coupled with changes in climatic conditions (e.g., snow pack, spring run-off phenology, precipitation patterns) will create significant wetland management and conservation challenges (Bedford and Douglas 2008). Today, the GSL is bordered along its eastern side by more than 160,000 acres of publicly (90,000) and privately (50,000) managed wetland habitat complexes (Utah Department of Natural Resources 2013). The Utah Division of Wildlife Resources (UDWR) manages eight Waterfowl Management Areas around the GSL, encompassing approximately 90,000 acres (Utah Department of Natural Resources 2013; Fig. 26). Bear River Migratory Bird Refuge, managed by the U.S. Fish & Wildlife Service, encompasses approximately 73,000 acres and was America’s first waterfowl sanctuary, established by Congress on April 23, 1928 (Utah Department of Natural Resources 2013). All private duck clubs and state owned areas manage wetland habitats for migratory waterbirds, particularly waterfowl. In managed wetland impoundments, emphasis is placed on producing submerged aquatic vegetation (SAV) including sago pondweed (Potamogeton pectinatus) and widgeon grass (Ruppia maritima; Kadlec and Smith 1983). Unmanaged wetlands occur along the east shore of GSL itself, and are west of levees that separate managed areas from the lake (Figs. 25, 26). The majority of unmanaged wetlands are classified under “state management authority”, which gives DWR the ability to create and manage for 4.27

possible future wildlife areas (Utah Department of Natural Resources 2013). The extent and composition of wetland habitat varies greatly with annual changes in lake level. Consequently, unmanaged areas can have greater variation in both emergent and submerged vegetation types, including pickleweed (Salicornia spp.) alkali bulrush (Scirpus maritimus), Olney three-square (S. americanus), hard-stem bulrush (S. acutus), purple loosestrife (Lythrum salicaria), and cattail (Typha spp.; Kadlec and Smith 1983).

Figure 26 M anaged wetland complexes in public (black shading) and private (gray shading) ownership and regions of unmanaged habitat (Bear River Bay, Ogden Bay, and Farmington Bay) in the Great Salt Lake System.

The GSL itself is a hypersaline terminal lake system located in north-central Utah within the Great Basin and Range Province and is a dominant water feature within the western United States (Arnow and Stephens 1990, Stephens 1990). At the average lake elevation of 4199.5 ft above sea level (range: 4,192.9–4,212.6 ft), the GSL encompasses approximately 1,700 mi 2 (range: 950–2,400 mi 2) with a maximum depth of approximately 33 ft (Arnow and Stephens 1990, Stephens 1990). The Southern Pacific

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GREAT SALT LAKE Railroad Causeway divides the GSL into two distinct areas with unique ecological characteristics (Figs. 25, 26). The North Arm of the GSL is characterized by minimal freshwater inflow, extreme hypersaline conditions (> 20% salinity) whereas the South Arm receives > 90% of the freshwater surface inflow into the GSL and consequently has lower salinity (Stephens 1990, Loving et al. 2002). Salinity concentrations vary inversely to lake levels in the GSL but have generally averaged 16% in the South Arm (range: 6–28%) which is approximately three times the salinity concentration of oceans (Arnow and Stephens 1990, Stephens 1990, Gwynn 2002). The South Arm is populated by green and blue-green algae, diatoms, and high biomass of halophile macroinvertebrates consisting primarily of brine shrimp (Artemia franciscana) and brine flies (Ephydridae sp.). Recent research has documented the hypersaline South Arm of the GSL as important habitat to several species of wintering waterfowl (Vest and Conover 2011). The GSL biological planning unit also encompasses Utah Lake which lies 30 miles south of the GSL and provides additional habitat for the greater GSL system population of waterfowl (Fig. 24). Utah Lake is a freshwater lake with extensive wetland habitat along its eastern and southern bays.

Summary Points 1. The GSL is a terminal system and was historically a dynamic complex of wetland and lake habitats for waterfowl and remains so today, though to a lesser degree. 2. GSL marshes are both expansive and diverse, have large areas of open water, and are rich in a variety of invertebrate and plant food resources. These features are the keystone of GSL’s value to migrating waterfowl. The evolution of waterfowl migrations through GSL is likely related to its historic importance in providing high-quality habitat during fall and spring migration periods. 3. GSL serves as a continentally important staging area for millions of waterfowl. It is essentially the crossroads of the West for waterfowl that link northern breeding areas in the US and Canada with terminal wintering areas such as the Central Valley of California, west coast and mainland of Mexico, and Gulf Coast. Peak waterfowl abundance occurs during late summer to early fall. 4. Significant anthropogenic alterations to the GSL watershed have reduced quantity and quality of water supplies available to the lake and associated wetlands.

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5. Waterfowl rely on both managed (public and private) and unmanaged wetland and lake complexes in the GSL system; some species utilize saline portions of the GSL during winter.

Population Objectives and Priority Species Peak waterfowl abundance in the GSL system occurs during fall migration and is lowest during the mid-winter period (Aldrich and Paul 2002). Therefore, as noted above, fitting mid-winter inventory data to NAWMP objectives to generate monthly or bi-weekly population estimates is inappropriate. Thus, alternative methods were developed for establishing period specific population objectives for GSL that maintain strong linkages to NAWMP. However, waterfowl population estimates for the entire GSL ecosystem are lacking. State and federally managed wetland complexes are currently surveyed on a systematic basis for waterfowl and other waterbirds, but survey methodologies are inconsistent. Additionally, large areas of public unmanaged and private properties remain unsurveyed. Thus, available population estimates for the GSL are likely grossly conservative (Aldrich and Paul 2002). Between August and April 2005-06 multiple waterfowl surveys were conducted in the GSL ecosystem that encompassed state and federally managed wetland complexes as well as portions of the GSL that are unmanaged and adjacent to managed wetland complexes (i.e., Bear River, Ogden, and Farmington Bays; Fig. 25). These unmanaged areas of the GSL are important waterfowl habitats but are typically not surveyed (Aldrich and Paul 2002). Thus, the fall–spring 2005-06 time period was chosen to characterize the spatial and temporal distribution of waterfowl abundance in the GSL ecosystem and to derive waterfowl population objectives because this time period comprised the most comprehensive set of waterfowl surveys to date during the migratory period. However, the 2005-06 time period was at the end of an extended regional drought and therefore temporal and spatial distribution of waterfowl may not be representative of “average” environmental conditions. Nevertheless, this was the most comprehensive data set available to characterize waterfowl use.

Managed Public Wetland Complexes The Utah Division of Wildlife conducts monthly (bimonthly during hunting season) ground surveys of all state waterfowl management areas (81,756 acres) in the GSL system, except the 1,380 acre Timpie Springs Wildlife Management area. Bear River Migratory Bird Refuge (BRMBR), a 73,000 acre wetland/upland complex adjacent

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GREAT SALT LAKE to the GSL and managed by USFWS, conducts bi-weekly (monthly minimum) surveys of all wetland dependent birds. Between October and April 2005-06, personnel from UDWR and Utah State University conducted monthly aerial waterfowl surveys on the GSL including Bear River, Ogden, and Farmington Bays which are adjacent to BRMBR and UDWR managed wetland complexes and are hydrologically connected to the GSL (Fig. 26). Surveys conducted on UDWR waterfowl management areas and at BRMBR did not encompass the total area of each management area. Staff from UDWR and BRMBR was contacted and estimates of proportional survey area on respective properties were obtained. These estimates (UDWR = 40%, BRMBR = 60%) were used to adjust population estimates on management areas (e.g., N UDWRt = N UDWRt / 0.4). Waterfowl abundance estimates from BRMBR weekly surveys were averaged during early (first 2 weeks of month) and late (last 2 weeks of month) time periods within months, when >1 survey/time period existed, to conform to UDWR survey periods. Monthly population estimates from the GSL aerial surveys were converted to bi-monthly estimates by assuming linear change in estimates between surveys. Estimates from each of the three surveys areas were then summed for each bi-monthly period October through April to obtain total waterfowl population estimates during the non-breeding period. Waterfowl abundance estimates were unavailable from the GSL aerial surveys in August and September 2005 because surveys were not initiated until October. We estimated GSL waterfowl abundance for August and September by applying the average ratio (= 0.80) of GSL abundance to UDWR and BRMBR abundance in October and November surveys because these months are ice-free portions of the fall migration period.

Privately Managed Wetland Complexes Tens of thousands of acres of wetland habitat occur in private ownership in the GSL system, many of which are managed to varying degree by duck hunting clubs and provide foraging habitat for waterfowl (Aldrich and Paul 2002, Johnson 2007. These areas are not surveyed however, and waterfowl abundance estimates are unavailable. Wetland management on private duck clubs generally mimics that of state WMAs and they possess

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similar levels of hunting pressure which can influence waterfowl abundance and distribution. Therefore, waterfowl abundance was estimated on private wetlands by calculating the density of waterfowl on UDWR management areas and applying that density estimate to known wetland complex acreages in private ownership for each month August through April. Additionally, Utah Lake, which lies approximately 30 mi south of GSL and is an important component of the GSL ecosystem for migratory birds, is not surveyed for waterfowl. The same density estimate derived from UDWR managed areas was applied to wetland acres in Goshen and Provo Bays in Utah Lake to account for waterfowl using the Utah Lake region within the GSL ecosystem. Abundance estimates from UDWR managed areas, BRMBR, GSL, and private wetlands were then summed to obtain an overall waterfowl abundance estimate for each month August through April.

Population Objectives To develop population objectives for the GSL system and link those objectives to the NAWMP the 2005 continental BPOP was assessed for the 10 most common surveyed duck species in the traditional survey area relative to NAWMP goals. All 10 species were below NAWMP goals at that time: Mallards (–17.6%), Northern Pintails (–54.3%), American Wigeon (–25.8%), Blue-winged and Cinnamon Teal (–2.4%), Redheads (–7.5%), Canvasback (–3.6%), and Scaup (–46.2%. Total GSL population estimates for these species were adjusted according to the NAWMP goals to develop GSL population objectives for each species. This process identified a peak population objective of 2.8 million waterfowl during fall migration (Fig. 27). This estimate approximated the lower bound of population abundance identified by Bellrose (1976, 1980) and provides an independent validation of population objectives identified for the IWJV. Daily population objectives were summed within 3 nonbreeding periods to obtain total waterfowl use-days. Fall migration was defined as August 15–November 30, winter as December 1–February 14, and spring migration as February 15–April 31. A total of 294.4 million duck use-days were estimated during the entire non-breeding in the GSL (Fig. 27). Use-days were then summarized by waterfowl guild (dabbling ducks, diving ducks, and swans and geese) for each time period (fall, winter, spring).

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GREAT SALT LAKE (12%), and Canvasback (11%); Tundra Swan and Canada Goose accounted for 9% of total use-days during spring.

Figure 27 Total waterfowl population objectives (gray bars) derived from waterfowl population estimates (black line) for the Great Salt Lake.

Northern Pintail and American Wigeon have been designated as Birds of Management Concern by the USFWS and are further classified as Game Birds Below Desired Condition. However, American Wigeon comprised a small proportion of dabbling duck objectives. The IWJV recognizes Northern Pintail as a priority dabbling duck species based on their FWS status and their contribution to the nonbreeding duck objectives. Redhead, Canvasback, and both Greater and Lesser Scaup have all been designated as Birds of Management Concern by the USFWS and as a Game Bird Below Desired Condition. The IWJV recognizes Scaup, Redhead, and Canvasback as priority species based on their USFWS status and their contribution to the diving duck objectives.

Fall Population Objectives

Limiting Factors/Species–Habitat Models

A total of 217 million waterfowl use-days were estimated during fall migration in the GSL system. Dabbling ducks comprised 93% of total waterfowl use during fall migration. Northern Pintail comprised 39% of dabbling duck use during fall followed by Gadwall (16%), Greenwinged Teal (13%), and Mallard (13%). Diving ducks comprised 6% of total waterfowl use-days. Ruddy ducks comprised 31% of diving duck use during fall migration followed by canvasbacks (21%), Redheads (21%), and Scaup (17%); Tundra Swan and Canada Goose contributed to roughly 1% of total waterfowl use. Winter Population Objectives A total of 17.4 million waterfowl-use-days were estimated during the winter period with dabbling ducks accounting for 74% of use-days. Northern Pintails accounted for 39% of dabbling duck use followed by Green-winged Teal (23%), Mallard (21%), and Northern Shoveler (11%). Diving ducks accounted for 19% of total waterfowl usedays during winter with Common Goldeneye comprising 91% of all diving duck use. Tundra Swan and Canada Goose combined accounted for 6% of total waterfowl usedays during winter. Spring Population Objectives A total of 60 million waterfowl-use-days were estimated during spring migration in the GSL system with a peak spring objective of 1.1 million waterfowl. Dabbling ducks accounted for 74% of total waterfowl use-days with Northern Pintail comprising 44%, Green-winged Teal 20%, and Northern Shoveler 10%. Diving ducks accounted for 20% of total waterfowl use-days during spring. Scaup accounted for 39% of diving duck use-days, followed by Common Goldeneye (18%), Ruddy Duck (18%), Redhead 4.30

Limiting factors and species-habitat models used to evaluate population carrying capacity are described previously in this chapter under the “Structure of the Nonbreeding Waterfowl Plan” section.

Conservation Design Landscape Characterization and Assessment: Waterfowl in the GSL rely on publicly and privately managed wetland complexes as well as unmanaged habitats to meet energetic demands during the nonbreeding period. Rapidly increasing human demand for water resources in the watershed will continue to divert fresh water from the rivers that supply wetlands and likely result in decreased wetland habitat available to waterfowl. To justify current and future water allocation for wetlands within the GSL system, managers and planners must be able to quantify the value of these habitats to waterfowl and other wetland-dependent wildlife. Managed wetlands include state, federal, and private lands contained within levees and actively managed as either waterfowl or wetland-dependent bird habitat. Unmanaged wetlands primarily include shallow water areas outside of levees that rely on freshwater outflows from the Bear, Weber/Ogden, and Jordan Rivers and are immediately adjacent to the GSL. These unmanaged wetlands are under no specified management regime and are under the greatest threat to water diversions because they are currently unprotected under Utah water laws. These unmanaged areas are characterized by highly dynamic water conditions and productivity. Additionally, they have been periodically inundated by the highly saline Great Salt Lake as a result of rising lake elevations from extended periods of high precipitation (Kadlec

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GREAT SALT LAKE and Smith 1989). Unmanaged wetlands are therefore highly variable with respect to the amount, distribution, quality, and availability of resources to waterfowl. Thus, understanding of their availability for planning purposes is limited. Recent research has attempted to quantify waterfowl food abundance in both managed and unmanaged wetland habitats in the GSL (Johnson 2007). This work focused on wetland habitats characterized as submerged aquatic bed dominated by sago pondweed and wigeon grass. This habitat type (SAV) is a management priority on publicly and privately managed impoundments to provide food resources for waterfowl. However, significant amounts of shallower wetland habitats containing seasonal emergent macrophytes such as alkali bulrush, Baltic rush, Olney three-square, and salt grass are also available in unmanaged regions and some managed impoundments. TRUEMET was used to assess the current ability of managed habitats to meet energetic demands of waterfowl at given population objective levels.

Model Inputs Time Periods Being Modeled The non-breeding portion of the annual cycle of waterfowl was divided into 3 time periods including fall migration, winter, and spring migration. The fall time period in the GSL is defined as early August 1–November 30, winter as December 1–February 14, and spring as February 15– April 30. Fall migration was divided into 8 time periods; 1) Aug1–14, 2) Aug15–31, 3) Sep 1–14, 4) Sep 15–30, 5) Oct 1–14, 6) Oct 15–31, 7) Nov 1–14, 8) Nov 15–30. The fall time period represents the time period between late summer and average freezing/icing conditions in the GSL marshes when waterfowl abundance is highest. Winter was divided into 5 time periods; 1) Dec 1–14, 2) Dec 15–31, 3) Jan 1–14, 4) Jan14–31, 5) Feb 1–14. Winter represents the time period of lowest ambient temperature in the GSL system, low availability of wetland habitat due to freezing conditions in freshwater wetlands and consequently lowest waterfowl abundance. Spring migration was divided into five time periods; 1) Feb 15–28, 2) Mar 1–14, 3) Mar 15–31, 4) Apr 1–14, 5) Apr 15–30. The spring time period represents the period of increasing temperatures, icefree conditions, and increases in both wetland biological activity and waterfowl abundance. Population Objectives by Time Periods The capacity of wetland habitats to meet energetic needs of waterfowl in the GSL was modeled on a bi-weekly basis from August to April 31 (Table 13). A description of how these population objectives were established can be found in the Biological Planning Section.

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Table 13 B i-weekly waterfowl population abundance objectives at the Great Salt Lake, Utah during the non-breeding season by dominant foraging guild. TIME INTERVAL

DABBLING DUCKS

DIVING DUCKS

SWANS & GEESE

TOTAL

Aug. 1-14

422,820

4,290

19,140

446,250

Aug. 15-31

1,560,380

21,290

23,310

1,604,980

Sep. 1-14

2,759,060

32,890

24,120

2,816,080

Sep. 15-30

2,076,260

74,410

14,440

2,165,100

Oct. 1-14

1,399,380

133,920

7,090

1,540,390

Oct. 15-31

1,396,110

181,050

10,440

1,587,600

Nov. 1-14

2,176,060

173,070

33,530

2,382,660

Nov. 15-30

1,405,700

234,540

56,370

1,696,620

Dec. 1-14

264,790

47,740

37,410

349,940

Dec. 15-31

182,060

43,840

10,150

236,050

Jan. 1-14

111,550

52,150

14,510

178,220

Jan. 14-31

96,560

48,470

6,300

151,330

Feb. 1-14

174,460

38,490

24,710

237,670

Feb. 15-28

392,990

57,420

35,820

486,230

Mar. 1-14

714,510

150,240

72,310

937,070

Mar. 15-31

860,940

184,140

90,950

1,136,020

Apr. 1-14

630,300

191,240

44,020

865,560

Apr. 15-30

363,130

171,690

4,830

539,650

Daily Energy Requirements The daily energy needs of waterfowl guilds were estimated during migration and winter by calculating a weighted body mass for each two-week time period to account for changes in species composition within foraging guilds. Species composition was determined from existing survey data in the GSL system (refer to Population Objectives in the Biological Planning Section). The average body mass of adult males and females was obtained for all species from Bellrose (1980) and a balanced sex ratio was assumed for each species. Body mass was assumed constant across time for all species. Habitat Availability and Biomass and Nutritional Quality of Foods Several wetland habitat types are available to waterfowl within the GSL system and can be categorized broadly as seasonal or permanent wetlands. Habitat characterizations and acreage estimates for privately and publicly managed impoundments were determined by available NWI data and interpretations of recent aerial photography (Ducks Unlimited unpublished data). Recent wetland

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GREAT SALT LAKE and vegetation mapping efforts conducted by Ducks Unlimited was used to identify and estimate the extent of primary foraging habitats for waterfowl in the GSL system. This mapping effort provided more detailed assessments of potential waterfowl foraging habitat than available from NWI because it relied on direct interpretation of vegetative associations. We categorized wetlands into three habitat classes: 1) submerged aquatic vegetation (SAV), 2) seasonal emergent wetlands, and 3) other wetlands. SAV wetlands were defined as areas of open water with <15% emergent vegetative cover and containing submerged macrophytes such as pondweeds and widgeon grass. The seasonal emergent wetland category included areas with either 1) >50% alkali bulrush as the dominant plant form, 2) wet meadows (>25% sedges and grasses), 3) playa/mudflats with >25% vegetative cover in salt grass, Salicornia, and/or alkali bulrush, and 4) other seasonal wetlands with emergent vegetation not dominated by invasive plants (i.e., phragmites, saltcedar) or permanent wetland plant associations (i.e., cattail, hardstem bulrush). The Other Wetlands category included 1) areas dominated by invasive plants, 2) permanent and semi-permanent wetlands with >75% vegetation cover in the form of cattails or bulrush, 3) playa/mudflat areas with no vegetation, or 3) riverine habitats. We assumed 75% of vegetated playa habitat was suitable as foraging habitat for modeling purposes due to interspersion of non-vegetated areas within this habitat type. We estimated a total of 95,660 acres of seasonal emergent and 54,150 acres of SAV foraging habitat (Table 14). SAV and seasonal emergent habitats were used to evaluate energetic carrying capacity of primary foraging habitats within the GSL system. SAV habitats are a primary management focus on public and privately managed wetlands and seasonal emergent habitats such as alkali bulrush habitats also receive considerable management attention in the GSL (Kadlec and Smith 1989). Consistent with the IWJVâ&#x20AC;&#x2122;s fall planning models for SONEC, permanent wetland areas dominated by robust emergent vegetation (i.e., cattail, hardstem bulrush) was not evaluated because their dense growth and vegetative structure generally make food resources unavailable to waterfowl. Estimates of SAV biomass were obtained from Johnson (2007) to calculate values of food density for waterfowl. Biomass estimates for seasonal emergent wetlands were obtained from habitat sampling efforts outside of GSL at other Great Basin wetland complexes in the Lower Klamath Basin of Oregon and California (Dugger et al. 2007). Plant communities were generally similar between GSL and those reported by Dugger et al. (2007). TME values from published sources were used to estimate food energy density (Petrie et al. 1998, Checkett et al. 2002, Kaminski et al. 2003, Nolet 4.32

et al. 2006, and Dugger et al. 2007). Biomass estimates of waterfowl food types were assigned to corresponding habitat acres for TRUEMET analyses. Table 14 E stimated acres of managed and unmanaged wetland habitat types in the Great Salt Lake planning area used to evaluate carrying capacity for non-breeding waterfowl. WETLAND HABITAT MANAGEMENT

SEASONAL SUBMERGED EMERGENT AQUATIC

OTHER

TOTAL

Managed

62,550

42,210

55,140

159,900

Unmanaged

33,110

11,940

308,860

353,900

Total

95,660

54,150

364,000

513,800

TRUEMET was used to model three scenarios in the GSL system which included combinations of managed and unmanaged habitats. First, waterfowl were allowed to forage in both managed and unmanaged habitats to evaluate the ability of potential resources in the GSL to meet energy demands of waterfowl. Second, waterfowl foraging was restricted to managed habitats only to evaluate the potential of managed habitats to meet population demands. Third, the ability of managed plus unmanaged habitats (total) to meet population demands were evaluated relative to recent hydrologic trends in the GSL system. Fall Migration Information from the published literature and expert opinion within the GSL system was used to assign percentages of which habitats and food types each guild likely uses to satisfy their daily energy demands during fall migration. For dabbling ducks, Cinnamon Teal, Green-winged Teal, Mallard, and Northern Pintail are assumed to meet all of their energy demand by foraging on seed resources. These seed resources are comprised of seeds obtained from SAV (e.g., sago pondweed seeds) and seasonal emergent habitats. A minimum foraging threshold of 30 lbs./acre was applied to seed resources (Naylor 2002). Prior to November 1, Gadwall and American Wigeon are assumed to meet all of their energy demands by foraging on leafy vegetation but after November 1, when leafy vegetation has senesced, they are assumed to meet all of their energy demands by foraging on seed resources. For diving ducks, all species are assumed to meet 25% of their food energy needs from leafy plant material, and 75% from tubers prior to November 1. After November 1, diving ducks are assumed to meet 100% of their energy demands from tubers. Prior to November 1, geese are assumed to meet 50% of their energy needs from

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GREAT SALT LAKE leafy vegetation and 50% from tubers, but after November 1 they meet all of their energy demands by foraging on tubers. Prior to November 1, swans are assumed to meet 10% of their needs from leafy vegetation and 90% from tubers, but after November 1, they meet all of their energy demands by foraging on tubers. A minimum foraging threshold of 50 lbs./acre was applied to sago tubers. Winter Waterfowl populations decline to their lowest levels during the winter time period at the GSL (Aldrich and Paul 2002, Fig. 14). Freshwater wetlands typically become frozen by mid-December and experience periods of thawing and freezing through winter depending on environmental and climatic conditions (Aldrich and Paul 2002). Thus, available food resources during winter are less predictable and most waterfowl emigrate from the GSL. However, several species including Northern Shoveler, Green-winged Teal, and Common Goldeneye may remain through the winter and forage on hypersaline invertebrates to meet part of their energy demands (Aldrich and Paul 2002, Vest and Conover 2011). These three species alone comprise 43% of the total winter population use-days. The GSL annually produces an immense biomass of brine shrimp (Artemia franciscana), brine shrimp cysts, and brine fly (Ephydridae spp.) larvae which these waterfowl species forage on (Vest and Conover 2011). Recent research by Utah Division of Wildlife Resources and Utah State University suggest that food resources on hypersaline wetlands are not likely to be limiting for these wintering waterfowl (Utah Division of Wildlife Resources unpublished data). Consequently, the energetic demands of waterfowl were not modeled during the winter time period relative to hypersaline resources. However, refined estimates of hypersaline invertebrate densities and their availability to waterfowl will prove useful for future conservation planning and management of GSL resources (Vest and Conover 2011). Although the availability of wetland resources is highly unpredictable during winter the same foraging assumptions described for fall migration were retained assuming if food resources were available wintering waterfowl would use them.

Model Results The capacity of SAV and seasonal emergent wetland habitats to meet the food energy needs of non-breeding waterfowl was evaluated on managed and unmanaged wetland complexes adjacent to the eastern side of the GSL (Fig. 26). It is estimated there are 54,150 acres of SAV and 95,660 acres of seasonal emergent habitat in the planning area (Table 14). It is estimated there are an additional 364,000 acres of other wetland types in the planning area which includes open water portions of Farmington and Ogden Bays associated with GSL. These other wetland habitats were not included in bioenergetic assessments. Below, model results are summarized with respect to foraging guilds and management types. SAV Guild: Managed and Unmanaged Habitats Energetic calculations identify 44,700 acres of SAV habitat are required in the GSL system to meet the needs of diving ducks, swans, and geese during the non-breeding period. These SAV habitats appear able to meet waterfowl energy demands in the GSL system based on food density, habitat availability, and foraging assumptions used in developing the carrying capacity model (Fig. 28). Model results suggest a surplus of food energy in potential SAV habitats, particularly during fall migration with most of the energy supply provided from managed habitats. The lack of strong difference between managed only and managed plus unmanaged scenarios resulted from relatively low acre estimate and lower tuber biomass for unmanaged SAV habitats (Johnson 2007). Diving ducks, geese, and swans would be unable to meet their energy demands on unmanaged SAV habitats alone.

Spring Migration The same foraging assumptions assumed during fall migration were applied during spring migration and therefore did not alter foraging assumptions for this time period. It was assumed no overwinter decomposition of food items occurred given the cold climatic (â&#x20AC;&#x201C;1°C average) conditions and therefore food resources carried through fall and winter into spring.

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Figure 28 Waterfowl population energy demand (black line) vs. habitat energy supplies in managed only (red dashed line) and in managed + unmanaged (red solid line) submerged aquatic vegetation (SAV) habitats at the Great Salt Lake.

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GREAT SALT LAKE Although these evaluations suggest sufficient SAV habitats exist, these analyses only reflect the potential of SAV habitats to meet waterfowl energy needs. SAV habitat estimates used here likely overestimate the amount of available acres. High evapotranspiration rates experienced at GSL (and throughout the Great Basin) result in rapidly declining water depths in impounded wetlands and can leave significant portions of these impoundments dry during the summer growing period unless adequate water supplies are provided. For example, Bear River Migratory Bird Refuge has only received 15% of its water delivery allocation between July and September over the last decade. Refuge managers plan that up to 75% of wetland units will dry because of reduced summer river flows and available water (Downard 2010). The refuge prioritizes which impoundments will receive the restricted water flows in order to achieve management objectives. However, in order to maintain adequate water flowing to priority impoundments requires a tradeoff of allowing other impoundments to dry out during this period. Reduced water flows also impacts the ability of the refuge and other management areas to provide water to important unmanaged SAV areas such as Willard Spur which lies south of the refuge boundary. Water availability in the GSL system is driven primarily by regional climatic conditions and diversions for agriculture and municipal uses. Water availability is therefore highly variable. Water inflows to the GSL system (including Bear River Migratory Bird Refuge) were, on average, 50% lower over the previous decade (2000–2010) compared to the long term average (1950–2010; Fig. 29). Consequently, SAV production has undoubtedly been reduced in this system over the past decade. Therefore, we also evaluated energetic carrying capacity of SAV habitats within the context of recent (i.e., 2000–2010) hydrologic trends (Fig. 29). Approximately 78% of SAV habitat occurs in the lower Bear River hydrologic component of the GSL system. We assumed that a 50% reduction in hydrologic inflows over the past decade (Fig. 29) resulted in a proportional reduction in available SAV habitats in the Bear River hydrologic portion of GSL. Consequently, we reduced the number of available SAV acres by these proportions to further evaluate energetic carrying capacity (i.e., 0.78 x 0.50 = 39% reduction in available SAV acres). This model identified a deficit in food energy just prior to peak population demand during spring migration (i.e., mid-March; Fig. 30). Given our assumptions of average SAV food energy density, an additional 9,300 acres of SAV habitat would be required to counter this energetic deficit. Given SAV habitat availability estimates may be biased high and the potentially lower surplus of SAV food energy 4.34

during spring (Fig. 30) it is plausible waterfowl relying on SAV habitats in the GSL system could experience a food energy deficit during the spring migration period.

Figure 29 Average water flows (cubic feet per second-CFS) measured at USGS gauging stations on the Bear, Ogden, and Jordan Rivers during three time periods: 1) 1950–2010 (long-term average), 2) 1980–1990 (corresponds to GSL flooding event), and 3) 2000–2010 (recent drought period).

Figure 30 Waterfowl population energy demand (black line) vs. habitat energy supplies in managed + unmanaged submerged aquatic vegetation (SAV) habitats (blue line) at the Great Salt Lake based on a 39% reduction in available acres from observed hydrologic declines over the past decade.

Dabbling Ducks: Managed and Unmanaged Habitats Energetic calculations identified 106,400 acres of seed producing habitat, primarily seasonal emergent habitats, are needed to meet the energy demands of dabbling ducks during the non-breeding period. Energetic assessments identified insufficient seed resources for dabbling ducks on managed habitats with energy deficits occurring by

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GREAT SALT LAKE the end of October within the fall migration period (Fig. 31). The addition of seed resources from unmanaged areas resulted in generally adequate food energy resources through fall migration and energy supply reached equilibrium with population demand by late November (Fig. 31). However, both managed only and managed plus unmanaged habitat scenarios suggest inadequate seed resources are available for spring migrating dabbling ducks. Overall, this assessment identified an additional 25,400 acres of seasonal emergent wetland habitat are needed to overcome energetic shortfalls in seed resources during the non-breeding period.

average seed energy density, an additional 52,600 acres of seed producing habitat (primarily seasonal emergent) would be required to counter this energetic deficit.

Figure 32 D abbling duck population energy demand (black line) vs. habitat energy supplies from seed resources in managed + unmanaged seasonal emergent habitats (blue line) at the Great Salt Lake based on a 34% reduction in available acres from observed hydrologic declines over the past decade.

Figure 31 P opulation energy demand (black line) vs. habitat energy supplies for dabbling ducks relying on seed resources in managed only (red dashed line) and managed + unmanaged (red solid line) seasonal emergent habitats at the Great Salt Lake.

Similar to SAV habitat assessments, seed resource assessments also assumed that all seasonal emergent habitat acres are available and suitable for foraging. In an attempt to more accurately reflect availability due to environmental conditions we applied a reduced habitat scenario similar to that conducted for SAV habitats. Approximately 67% of inventoried seasonal emergent habitat on the eastern portion of GSL (Ducks Unlimited, unpublished data) occurs in the lower Bear River component. We assumed that a 50% reduction in hydrologic inflows over the past decade (Fig. 29) resulted in a proportional reduction in available seasonal emergent habitats in the Bear River hydrologic portion of GSL. Therefor, we reduced the number of available acres by these proportions to further evaluate energetic carrying capacity (i.e., 0.67 x 0.50 = 34% reduction in available seasonal emergent acres). This model identified a deficit in food energy occurring in late October prior to peak energy demand (Fig. 32). Given our assumptions of 4.35

Model Interpretations Waterfowl remain abundant in the GSL system through fall with estimates of dabbling ducks alone exceeding 1 million in October and November. Clearly, dabbling ducks in the GSL system must be able to obtain food resources exceeding the estimates used for seed resources in these models. The disparity between seed energy supply versus dabbling duck population demands requires exploration of mechanisms that may influence this disparity. First, the foraging assumptions may require refinement. If either SAV vegetation or tubers are an important component of dabbling duck diets (save for Gadwall and American Wigeon), these models will require appropriate adjustments. Similarly, if aquatic invertebrates are important food resources for waterfowl then it will be necessary to re-parameterize these models. Kadlec and Smith (1989) identified the need for better information relating waterfowl food resources to waterfowl physiological requirements in Great Basin marshes, including GSL. Unfortunately, little progress has been made during this time and reliable estimates of waterfowl resource selection at the GSL is currently lacking. Secondly, estimates of seed biomass obtained from other Great Basin marshes may not be an adequate proxy for seed biomass in the GSL system. However, seed biomass estimates from emergent marsh habitats in the GSL are currently unavailable and plant communities

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GREAT SALT LAKE in habitats dominated by alkali bulrush were generally similar between locations. Thirdly, many bioenergetics analyses have ignored, as here, the potential value of other wetland habitats to provide food resources to waterfowl. Waterfowl managers have been reasonably successful in reliably estimating waterfowl food resources in agriculture (e.g., Stafford et al. 2006) or intensively managed moistsoil habitats (e.g., Naylor et al. 2005, Kross et al. 2008). However, waterfowl managers have been less successful at deriving reliable estimates from other wetland habitats including unmanaged areas. In summary, investments to improve understanding of wetland productivity and waterfowl resource selection at the GSL will greatly improve wetland management strategies there. Conservation Needs These analyses highlight several key information needs in the GSL that are required to fully inform whether current wetland resources are able to meet the physiological requirements of non-breeding waterfowl. Primarily, reliable biomass estimates of potential waterfowl foods are needed in managed and unmanaged emergent wetland habitat. Improved understanding and estimation of the spatiotemporal variability of wetland resources are needed to better inform conservation targets. Additionally, improved understanding of waterfowl resource selection in the GSL system is needed to refine foraging guild assumptions. Although uncertainty exists in these energetic carrying capacity assessments, these models generally suggest that waterfowl relying on SAV vegetation and tubers likely have sufficient resources during fall migration. However, this relationship is more tenuous during spring migration. Consequently, maintaining existing management infrastructure and capabilities on privately and publicly managed SAV habitats in the GSL will be vital to ensuring waterfowl population demands are met. Perhaps the greatest conservation challenge for meeting waterfowl, and other wildlife, population demands in the GSL system will be the access to sufficient water supplies. Water is needed not only to meet the needs of managed marshes but also to supply the expanse of unmanaged wetlands that exist below dikes (Aldrich and Paul 2002). Water needs have long been recognized, but assessments of wetland water requirements have not been comprehensively assessed in the GSL system since Jensen (1974) estimated 1.5 million acre-feet of water is required annually to sustain GSL marshes. This represents approximately 80% of the 1.9 million acre-feet of surface inflow reaching the main body of the GSL itself. The IWJV is unaware of any comprehensive assessment of

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water held by state, federal, and private interests for wetland management in the entire GSL system. Intense demands to transfer â&#x20AC;&#x153;surplusâ&#x20AC;? water to municipal use may ultimately limit water delivery capacity (Aldrich and Paul 2002, Bedford and Douglas 2008, Downard 2010). For example, the Utah Division of Water Resources has been directed to develop an additional 275,000 acre feet of Bear River water to support the rapid population growth in the Wasatch Front although many Bear River water users believe the system is already fully allocated (Downard 2010). Thus, identifying and quantifying water needed to meet waterfowl objectives will be a critical step for wetland conservation. Providing reliable water delivery for wetland systems will require innovative and collaborative approaches with a diverse group of stakeholders. Water quality issues in the GSL system are also of significant concern to wetland and wildlife managers. Elevated concentrations of some environmental contaminants (e.g., mercury, and selenium) have been detected in the GSL system including waterfowl and other wetland dependent birds (Naftz et al. 2008; Vest et al. 2009; Conover and Vest 2009a,b). High nutrient loading into GSL wetlands, especially in Farmington Bay wetlands, has caused extensive algal blooms and mats to limit the productivity of SAV beds and alter invertebrate community dynamics. Consequently, foraging resources for waterfowl have been reduced. Another primary stressor to the availability of waterfowl foraging habitats is the persistence of exotic plants in the GSL, primarily Phragmites (common reed) and tamarisk (salt cedar). Invasion and spread of phragmites throughout the GSL system has significantly diminished the quality of both managed and unmanaged wetland habitats. Dense, monotypic stands of phragmites have replaced native vegetation such as alkali bulrush and other seedproducing wetland plants. Recent mapping efforts suggest over 23,000 acres of phragmites occur in the GSL system (Lexine Long, Utah State University, unpublished data). Treatment of these exotic plants and restoration back to native plant communities that provide food resources for waterfowl could meet up to 90% of the seed energy deficit identified in carrying capacity evaluations. Control of exotic and undesirable plant communities at GSL will be a continual challenge for wetland habitat managers and conservation partners. Consequently, wetland restoration and enhancement activities that addresses exotic plant stressors will play a prominent role in meeting waterfowl objectives in the GSL landscape.

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COLUMBIA BASIN Biological Planning Spatial Planning Unit The Columbia Basin (CB) planning unit encompasses most of eastern Washington and the northern portion of Gilliam, Morrow, and Umatilla counties in Oregon (Fig. 31). Elevations range from 160 feet above sea level along parts of the Columbia River to nearly 4,000 feet on isolated hills. Precipitation increases from west to east, with most of the region receiving between 8 and 14 inches annually. With its low elevations and moderating maritime effect annual temperatures average between 40 °F and 57 °F, though temperatures can range from sub-zero to over 100 °F.

Figure 33 T he Columbia Basin Spatial Planning Unit of eastern Washington.

Prior to the initiation of the Yakima and Columbia Basin Irrigation Projects the CB consisted mostly of arid shrub-steppe lands and provided relatively little waterfowl habitat. Delivery of irrigation water from the Yakima began in 1910 while the Photo by Ducks Unlimited, Inc. Columbia Basin projects began in 1950 respectively. The Yakima Irrigation Project was initiated in the early 1900’s and largely completed by the 1930’s while the Columbia Basin Project was largely constructing during the 1950’s and 1960’s, with lesser acreage added sporadically through the 1980’s.

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The Yakima and Columbia Basin projects brought water to the desert and fundamentally changed the landscape from desert to agriculture. Nearly 65,000 acres of corn was being grown annually in Photo by Ducks Unlimited, Inc. the Basin by 1960. Development of the irrigation projects not only provided field feeding opportunities for waterfowl, but also resulted in the impoundment and subsequent manipulation of water levels on the Snake and Columbia rivers (Ball et al. 1989). These impoundments provided roosting habitats that were adjacent to abundant food supplies, remained largely ice-free, and provided a refuge from hunting. In some impounded areas water depths were shallow enough to support submerged aquatic vegetation (SAV) and some river stretches like Wells Pool became known for their phenomenal SAV production. Ice age floods that originated from Glacial Lake Missoula had previously carved topographical depressions throughout the CB, and many of these filled with water as the Yakima and Photo by Ducks Unlimited, Inc. Columbia Basin irrigation projects raised water tables in the region. The best known of these water bodies is the 27,000 acre Potholes Reservoir, which serves as a major storage facility for irrigation water. Irrigation runoff from farmlands is now channeled through other drainage ways such as the Winchester and Frenchman Wasteways and returned to the Potholes Reservoir for future use. The combination of topographical depressions and a rising water table resulted in thousands of acres of seep wetlands and lakes throughout the CB. Although most of the wetlands that resulted from the irrigation projects are largely “unmanaged”, they initially provided important waterfowl foods. However, food production in these wetlands is thought to have declined as a result of wetland succession, invasive plant species, and carp infestation. In fact, recent sampling of plant communities in them indicated little or no production of waterfowl foods. Today, most of the wetlands that provide abundant waterfowl food sources during fall and winter are likely confined to publicly managed habitats (Washington Department of Fish and Wildlife 2007).

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COLUMBIA BASIN Mallards quickly responded to the combination of irrigated agriculture and newly created roosting and wetland habitat. Mid-winter counts of Mallards in the CB remained fairly steady between 50,000 and 100,000 between 1943 and 1950, then increased steadily to a peak of over 1,000,000 birds in January 1964 (Fig. 32). Since then Mallard numbers have varied widely. Mid-winter counts declined from the late 1960’s through the 1970’s before rebounding somewhat in the 1980’s and early 1990’s. During the past decade Mallard numbers have been significantly lower compared to most of the previous forty years. Mallards remain by far the most abundant duck in the CB during fall migration and wintering periods, however, accounting for about 60 percent of all dabbling ducks present in October and 85–90 % of those present in November through February (Fig. 33). Scaup (lesser and greater spp. combined) account for 50–60% of wintering diving ducks (Fig. 34).

Figure 36 S pecies composition of diving duck populations surveyed in the Columbia Basin from October to February. Results based on average monthly counts from mid-1970’s – mid-2000’s.

Although it is widely accepted that Mallard numbers in the CB are higher than in the pre-irrigation era it seems likely that American Wigeon and some species of diving ducks like Scaup have increased as well. These species would have benefited from an increase in SAV along impounded areas of the Columbia and Snake Rivers. Not surprisingly, American Wigeon are the second most abundant dabbling duck in the Columbia Basin and their numbers are higher now than at any time since the 1970’s (Fig. 35). Scaup numbers in the CB are also highest now since surveys were begun in the 1970’s (Fig. 36).

Figure 34 M id-winter Mallard counts in the Columbia Basin from 1955-2010.

Figure 37 Average peak counts of American Wigeon in the Columbia Basin from the 1970’s–2000’s. Peak American Wigeon counts usually occurred during November.

Figure 35 S pecies composition of dabbling duck populations surveyed in the CB from October to February. Results based on average monthly counts from mid 1970’s – mid 2000’s.

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COLUMBIA BASIN

Figure 38 Average peak counts of Lesser and Greater Scaup (combined) in the Columbia Basin from the 1970’s–2000’s. Peak Scaup counts usually occurred during November.

For species that are not strongly associated with agriculture or do not rely on SAV the benefits of irrigation are less clear, Northern Pintails and Green-winged Teal providing cases in point. Populations of both species in the CB appeared to have been highest in the 1970’s or 1980’s but declined thereafter (Fig. 37). Both species are known to rely heavily on wetland plants that produce abundant seeds, and the decline in wetland productivity throughout the CB may have made the region less attractive over the past 20 years. However, even peak counts of Northern Pintail and Green-winged Teal using the CB in the 1970’s and 1980’s were relatively small compared to those in most migration and wintering areas (e.g., Central Valley of California). Although a decrease in wetland productivity may have also contributed to the recent decline in Mallard numbers, Mallard diets in the CB even thirty years ago were almost exclusively corn (Rabenberg 1982).

Irrigation has undoubtedly increased the amount of wetland habitat available to fall migrating and wintering waterfowl in the CB. However, both the Yakima and Columbia Basin irrigation projects also resulted in the large-scale loss of floodplain wetlands (Washington Department of Fish and Wildlife 2007). Most floodplain wetlands in the CB were likely seasonal in nature and may have received most of their water in spring when river and creek flows were highest. This would have made them especially important to spring-migrating waterfowl. Floodplain habitat has also been lost outside of the irrigation project areas. Levees, overflow drainage canals, and large diversion structures have been constructed to regulate creek flows and protect floodplain farm fields from unwanted flooding. These alterations have completely changed the hydrology of many primary and secondary streams and their associated wetlands throughout the CB. Many of these streams are largely disconnected from their floodplain which has undoubtedly resulted in the loss of spring migration habitat.

Summary Points 1. Irrigation projects in the CB have greatly increased the region’s attractiveness to waterfowl compared to historic times. Irrigation has produced abundant field feeding opportunities and large amounts of roosting habitat by creating new wetlands and river impoundments. 2. Although Mallard numbers in the CB have varied widely over the past fifty years, they continue to dominate the region’s overall duck population. Populations of other dabbling and diving duck species are low compared to other major wintering areas, though some species such as American Wigeon and Scaup likely exceed historic levels because of increases in SAV. 3. Many of the wetlands that resulted from the irrigation projects have declined in terms of waterfowl food production. Although species such as Northern Pintail and Green-winged Teal may have been negatively affected by this decline in productivity, these species were never abundant even when their populations peaked in the CB during the 1980’s.

Figure 39 Average peak counts of pintail (black) and greenwinged teal (gray) in the Columbia Basin from the 1970’s–2000���s.

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4. Although irrigation has undoubtedly increased the overall amount of wetland habitat in the CB, net losses have likely occurred in floodplain wetlands historically important to spring migrating waterfowl.

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COLUMBIA BASIN Population Objectives and Priority Species Joint Ventures have been encouraged to identify priority waterfowl species and to develop explicit population objectives for these species. The JV recognizes three waterfowl groups based on habitat use and foraging ecology -- dabbling ducks, diving ducks, and geese and swans. Where possible, population objectives were established for all species in a waterfowl group. Priority species were then identified based on the designation as USFWS bird of management concern, and the relative abundance of a species in its waterfowl group. Biological requirements of these priority species are discussed below.

Columbia Basin Ducks In 1986 the NAWMP developed continental population objectives for North American duck species based on environmental conditions and breeding waterfowl numbers from 1970–1979. Waterfowl populations in the 1970’s met the demands of both consumptive and non-consumptive users and provided a basis for future conservation efforts. Population objectives from the NAWMP have been “stepped down” to Joint Ventures that support migrating and wintering waterfowl. By combining information from the mid-winter waterfowl survey with estimates of waterfowl harvest and mortality, population objectives for the mid-winter period (early January) were established for all counties in the U.S. Counties were then combined to develop Joint Venture mid-winter population objectives (Koneff 2003). The NAWMP mid-winter objective for dabbling and diving ducks in the CB is presented in Table 15. Mallards account for 82% of the dabbling duck objective, American Wigeon 12%, Northern Pintail 3%; Green-winged Teal,

Northern Shoveler, and Gadwall account for the remaining 3%. Scaup account for nearly 80% of the diving duck mid-winter objective, while Canvasback, Ruddy Duck, Redhead, and Ring-necked Duck make up the rest. Population objectives stepped down from the NAWMP only apply to the mid-winter period, but, migrating and wintering waterfowl are present in the CB for several months and population objectives must be established for this entire time period as well. Other Joint Ventures that support large numbers of migrating and wintering waterfowl typically establish population objectives on a bi-weekly or monthly basis (e.g., Central Valley Joint Venture 2006). In some cases these bi-weekly or monthly population objectives are developed by combining the Joint Venture’s mid-winter NAWMP objective with data on waterfowl migration chronology (Petrie et al. 2011). For example, assume that a Joint Venture has a mid-winter (January) NAWMP objective of 100,000 dabbling ducks. Monthly surveys indicate that dabbling duck numbers in November average 80% of January numbers. Thus, the population objective for November is 80,000 birds (0.8 * 100,000). The advantage here is that the November objective is tied to the NAWMP by “fitting” migration data to the NAWMP mid-winter objective. Washington Department of Fish and Wildlife has conducted monthly surveys of waterfowl in the CB since 1975 using fixed-wing aircraft. These surveys include all months from October through February, though February surveys were discontinued after 1984. The JV fitted this migration data to NAWMP mid-winter objectives for all dabbling and diving duck species in the CB to generate monthly population objectives between October and February (Table 16).

Table 15 C olumbia Basin mid-winter duck population objectives. Mid-winter population objectives do not necessarily correspond to peak population objectives. BIRD GROUP/ PRIORITY SPECIES

MID-WINTER POPULATION OBJECTIVEB

U.S. FISH & WILDLIFE SERVICE STATUS

CONTINENTAL POPULATION STATUS C

Dabbling Ducks

686,494

Mallard

561,747

GBBDC

No trend

American Wigeon a

83,272

GBBDC

Decreasing

Northern Pintail a

22,399

GBBDC

Decreasing

GBBDC

Decreasing

a

Diving Ducks Scaup a

101,011 80,225

Priority species Mid-winter population objective derived from the North American Wildlife Management Plan c Population trend 1970-2006 GBBDC – Game Birds Below Desired Conditions a

b

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COLUMBIA BASIN Table 16 M onthly population objectives for dabbling ducks, diving ducks, and geese in the Columbia Basin.

SPECIES Mallard

OCTOBER

NOVEMBER

DECEMBER

JANUARY

FEBRUARY

147,335

555,243

642,369

561,747

328,755

American Wigeon

99,345

114,915

111,584

83,272

51,629

Northern Pintail

20,608

31,359

28,223

22,399

17,247

Green-Winged Teal

24,815

32,590

20,513

16,543

8768

Gadwall

1,835

1,850

1,195

7,71

995

Northern Shoveler

3,084

3,947

3,207

1,762

1,057

297,022

739,904

807,091

686,494

408,451

73,005

110,711

111,513

80,225

100281

Canvasback

6,137

8,486

9,471

7,577

7,425

Redheads

6,158

4,495

3,325

3,079

2,340

Ring-necked Duck

2,540

3,852

3,879

2,791

3,489

Ruddy Duck

6,678

10,128

10,201

7,339

9,173

94,518

137,672

138,389

101,011

122,708

391,540

877,576

945,480

787,505

531,159

43,313

60,865

39,979

25,860

ND

Dabbling Ducks Scaup

Diving Ducks Total Ducks Canada Geese ND â&#x20AC;&#x201C; No t D e t e r mi n e d

Aerial surveys of waterfowl in the CB are not available for March and April so establishing population objectives using the method above is not possible for these months. However, during winter 2000â&#x20AC;&#x201C;2003 one hundred and forty female Northern Pintails were captured in the Central Valley of California and fitted with back-mounted satellite transmitters (Miller et al. 2005). One objective of this study was to identify spring migration routes and staging areas used by Northern Pintails prior to arrival on the breeding grounds. Most Northern Pintails that use the CB in spring probably originate from wintering populations in California and southern Oregon. If Northern Pintails marked with satellite transmitters in the Central Valley are representative of these wintering populations and the size of these populations is known, then the fraction of marked birds located in the CB may be used to establish a spring pintail population objective. Mid-winter population objectives for pintails have been stepped down from the NAWMP to all California and southern Oregon counties. Collectively these midwinter objectives total 3,004,000 birds. A more complete description of how these mid-winter objectives were established can be found below in the SONEC section of this plan. Five percent of all birds marked in the Central Valley were located in the CB during April (Miller et al. 2005). Assuming that 5% of all pintails wintering in 4.41

California and southern Oregon migrate through the CB in April, then up to 150,000 pintails may rely on the CB in spring (Fig. 38). Unfortunately, it is not possible to estimate the number of other waterfowl that might use the CB during spring migration. However, mid-winter population objectives for all dabbling ducks in California and southern Oregon total 6,085,000 birds. If five percent of these birds also use the CB in spring this would equal roughly 300,000 ducks.

Figure 40 M onthly population objectives for Northern Pintails in the Columbia Basin

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COLUMBIA BASIN Mallards, Northern Pintail, and American Wigeon have all been designated as birds of Birds of Management Concern by the USFWS and are further classified as Game Birds Below Desired Condition. The IWJV recognizes Mallards and American Wigeon as priority dabbling duck species based on their USFWS status and their contribution to the dabbling duck mid–winter objective (Table 15). Although selecting priority species based on mid-winter abundance can overlook dabbling ducks that reach peak numbers during fall or spring, Mallards and American Wigeon remain the most numerous dabbling duck species in the CB from October through February (Fig. 33). Although Northern Pintail numbers in the CB are relatively low during these months, they are also considered a priority species. This designation was due to the likelihood that significant numbers of Northern Pintail use the CB during spring (Fig. 38). Between 1970 and 2006 continental Mallard populations showed no significant trend while populations of American Wigeon and Northern Pintail declined (Table 15). Continental populations of nonpriority species including Green-winged Teal, Gadwall, and Northern Shovelers all increased during this period (North American Waterfowl Management Plan Continental Progress Assessment 2007). Both Greater and Lesser Scaup have been designated as Birds of Management Concern by the FWS and are further classified as a Game Bird Below Desired Condition. The JV recognizes scaup as priority species based on their FWS status and their contribution to the diving duck goal (Table 15). While other diving ducks have been given similar FWS status they are not considered priority species due to their low numbers in the CB. Moreover, continental populations of non-priority diving duck species in CB increased or were stable between 1970 and 2006 (Progress Assessment of the North American Wildlife Management Plan 2007). Geese Many North American goose and swan populations have significantly increased from the 1970’s or have undergone major changes in wintering distribution. As a result, Joint Ventures are advised to use more recent information when establishing population objectives for geese and swans (M. Koneff pers. comm.). Nearly all geese that occur in the CB during the non-breeding period belong to the Pacific population of western Canada geese (Branta canadensis moffitti). To establish monthly population objectives counts of Canada geese were averaged from 2001 to 2005 (Table 16).

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Fitting migration data to a NAWMP mid-winter objective is recommended for areas like the CB that experience peak bird abundance at or near the mid-winter period (Petrie et al. 2011). However, this approach does not work well for planning units that largely serve as migration habitat. In these areas peak bird abundance usually occurs in spring or fall, and mid-winter populations are often small. NAWMP mid-winter objectives for these areas are correspondingly small and are likely associated with a high degree of sampling error. As a result, fitting migration data to these NAWMP objectives to generate monthly or bi-weekly population objectives is not recommended (Petrie et al. 2011).

Limiting Factors/Species–Habitat Models Limiting factors and species-habitat models used to evaluate population carrying capacity are described previously in this chapter under the “Structure of the Nonbreeding Waterfowl Plan” section.

Conservation Design Landscape Characterization and Assessment: Columbia Basin Factors Influencing Mallard Numbers in the CB: A Review of Earlier Work Prior to conducting an analysis of carrying capacity some of the factors thought to influence Mallard numbers in the CB were reviewed. Mallards make up 85–95% of all dabbling ducks in the CB and rely on corn for > 95% of their diet after mid-November (Fig. 33: Rabenberg 1982). Parallel changes in Mallard numbers and field corn acreage in the CB have attracted the interest of waterfowl managers for over 50 years (Lauckhart 1961, Galbreath 1962). In the 1940’s and early 1950’s midwinter Mallard numbers in the CB remained relatively constant between 50,000 and 100,000 birds during a time when less than 10,000 acres of corn was planted annually in the CB (Rabenberg 1982). Between 1952 and 1959 corn production in the CB increased from 7,500 acres to nearly 65,000 acres (United States Department of Agriculture National Agricultural Statistics Service [USDA-NASS] 2005). In 1955 the USFWS began standardized mid-winter waterfowl surveys. From 1955 to 1959 mid-winter counts of Mallards in the CB increased from 280,000 to 840,000 birds (Fig. 39).

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COLUMBIA BASIN

Figure 42 P eriods of increase and decline in Columbia Basin mid-winter Mallard counts from 1955–2006. Orange line identifies period trends.

Figure 41 M id-winter Mallard counts and acres of planted corn in the Columbia Basin from 1955–1980.

The initial increase in CB Mallard populations was influenced by increases in corn acreage. However, beginning in the early 1960’s the relationship between corn production and Mallard numbers became less clear and not necessarily one of cause and effect (Ball et al. 1989). From 1960 to 1980 there was no correlation between mid-winter Mallard counts and the amount of corn planted in the Columbia Basin; when Mallard numbers peaked in 1964 corn acreage had declined 50% since 1960 (Fig. 39; Ball et al. 1989). Mid-winter counts of Mallards in the CB significantly declined from the mid 1960’s through the late 1970’s (Fig. 39). The decline prompted further research into factors influencing CB Mallard numbers. Buller (1975) first suggested that Mallard numbers in the CB may be partially dependent on breeding distribution the previous breeding season. Breeding Mallards displaced from the southern Alberta prairies during drought migrate into northern Alberta, Alaska, and the Northwest Territories (Hansen and McKnight 1964, Pospahala et al. 1974). This northwest “shift” of Mallards during drought periods aligns them geographically with the CB and may increase the probability that these birds migrate through the CB (Fig. 40). Banding data indicate that areas northwest of southern Alberta supply 50–60% of the Mallards harvested in Washington and Oregon and may provide an even greater percentage of the Mallards present in the CB during mid-winter (Munro and Kimball 1982). 4.43

Rabenberg (1982) examined the relationship between midwinter Mallard populations in the Columbia Basin and numerous variables. Ball et al. (1989) provide a summary of this work; “Estimated Mallard breeding populations in southwest Alberta were negatively correlated with those in Alaska and the Yukon. Wintering Mallard populations in the CB were negatively correlated with those the previous spring in southwest Alberta. In addition, midwinter Mallard numbers in the CB were positively associated with warmer temperatures in November and negatively associated with snow cover in January.” The IWJV concludes that, although corn is responsible for attracting large numbers of wintering Mallards to the CB and is necessary to sustain these populations, other factors are important also. The size of the Mallard population remaining in the CB during early January (the time of mid-winter surveys) seems to depend partly upon distribution of birds on breeding grounds the previous spring and partly upon the influences of early winter weather patterns on Mallard arrival dates, rates of southward migration, chronology of the corn harvest, and snow and ice cover. The conclusion of Rabenberg (1982) that mid-winter Mallard numbers in the CB were likely to be higher in drought years is particularly interesting. Mid-winter Mallard counts in the early 1960’s were among the highest ever recorded in the CB even though the Canadian Prairies were in a period of significant drought. Conversely, Mallard numbers in the CB during much of the 1970’s were half that of the early 1960’s despite breeding conditions in prairie Canada in the 1970’s being favorable (Fig. 39). Finally, the Rabenberg (1982) analysis of Mallard numbers in the CB relied on data from 1952 to 1980. Beginning in 1981 mid-winter counts of Mallard began to rise in the CB and stayed high throughout much of that decade (Fig. 32). High CB Mallard numbers in the 1980’s coincided with

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COLUMBIA BASIN another drought on the Canadian prairies and seemed to support Rabenberg’s earlier conclusions.

Factors Influencing Mallard Numbers in the CB: An Updated Analysis Nearly thirty years have elapsed since Rabenberg’s analysis and the subject was revisited for this plan using data from 1955–2006. Rabenberg (1982) focused on the relationship between mid-winter Mallard numbers, weather, corn production, and the distribution of breeding Mallard populations the previous spring. The updated analysis excluded effects of winter weather and evaluated the relationship between mid-winter Mallard numbers, corn production, and breeding Mallard distribution. The overall conclusions of that analysis and a general discussion of this approach are found below. This analysis included all years between 1955 and 2006, and, mid-winter Mallard counts displayed little overall trend over that time period. However, two relatively distinct periods of mid-winter Mallard population increases and two periods of decline have occurred over the 50-year period. The first period of increase occurred between 1955 and 1964, and the first period of decline occurred between 1964 and 1979. These first two periods were adopted from Rabenberg (1982), though his data set actually spanned 1952–1980. The second period of increase occurred between 1979 and 1992. After 1992 mid-winter Mallard counts entered another period of decline (Fig. 40). For all years as well as for each of the four time periods mid-winter Mallard counts were modeled as a function of planted corn acres, the number of Mallards counted in southern Alberta (SAB) during breeding pair surveys, and the number of Mallards counted in northwest (NW) breeding pair strata. Mallard counts were also modeled as a function of these three variables for 1956–1979, which generally corresponds to the period of Rabenberg’s (1982) analysis. An information theoretic approach and Akaike’s information criteria (AIC) was used to select the ‘best” approximating model. SAB was defined as breeding pair strata 26–29, and strata 75. The NW breeding pair strata included strata 13–15, 17, and 76–77 of the annual North America Breeding Waterfowl Population and Habitat Survey. NW strata were assumed to cover areas in which drought displaced Mallards from SAB are likely to be observed during the breeding pair survey. Rabenberg (1982) had included Alaska as another area that might contain drought displaced birds but the state was not included here. Alaska has experienced significant increases in breeding Mallard numbers since the 1970’s and including it likely would have confounded some results. 4.44

For all years (1955–2006) the best approximating model for explaining mid-winter Mallard counts in the CB included SAB Mallards. No other explanatory variables (i.e., corn acres or NW strata) were retained in this best fit model. However, the relationship between CB Mallards and SAB Mallards was weak (Fig. 41). Moreover, Rabenberg (1982) found a negative or inverse relationship between CB Mallards and SAB Mallards while the current analysis suggested a slightly positive relationship. For the first period of increase (1956–1964) none of the three explanatory variables were retained and there was no best fit model. In other words, CB wintering Mallards showed no relationship of any kind to corn, or to breeding Mallard populations the previous year in either SAB or NW strata. For the first period of decline (1964–1979) the best approximating model included only corn. However, the relationship between CB Mallards and corn was negative, indicating that the relationship was spurious and had no biological basis (Fig. 42). For the second period of increase (1979–1992) the best model included only NW strata. However, the relationship between CB Mallards and NW strata was negative. Rabenberg (1982) suggested that a positive relationship between CB Mallards and the number of drought displaced Mallards might exist, though he also found no statistical evidence for this. For the second period of increase (1992–2006) the best model explaining CB Mallard counts included only SAB Mallards. However, the relationship was again positive, not negative as Rabenberg (1982) had found. For the period that corresponded to the Rabenberg (1982) analysis (1955–1979) none of the three explanatory variables were retained and there was no best fit model.

Figure 43 T he relationship between mid-winter counts of mallards in the Columbia Basin (CB) and the size of mallard breeding populations in southern Alberta (SAB) the previous spring.

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COLUMBIA BASIN

Figure 44 R elationship between total corn acres and midwinter mallard counts in the Columbia Basin years 1964–1979.

This updated analysis supported the earlier conclusion by Rabenberg (1982) that corn acres were not responsible for fluctuations in Mallard numbers. Rabenberg (1982) also found some evidence that numbers in the CB were inversely related to breeding Mallard populations in southern Alberta. However, we found no indication that Mallard numbers in the CB were dependent on the distribution of breeding Mallards the previous spring, either through a positive relationship with NW strata or a negative relationship with SAB Mallards. It may be worth noting that the Rabenberg (1982) analysis included years prior to 1955 and that the statistical relationship between CB Mallards and Mallards in southern Alberta was not especially strong. Mid-winter Mallard counts in the Columbia Basin have been depressed for nearly 20 years relative to bird numbers in the early 1960’s, early 1980’s, and early 1990’s (Fig. 32). Most Mallards that winter in the CB originate from breeding populations in SAB or from areas that correspond to the NW strata (Rabenberg 1982). Regardless of how the distribution of breeding Mallards may influence CB Mallard numbers from year to year, SAB and the NW strata collectively represent critical “source areas” for CB birds. Unfortunately, breeding pair survey indicates that the total number of Mallards in SAB and the NW strata has significantly declined since the 1950’s (Fig. 43). Most of this decline has occurred since the mid-1970’s with declines in SAB Mallards accounting for the majority of loss. Regardless of the influence of Mallard breeding distributions there are fewer Mallards currently available to migrate into the CB compared to the past.

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Figure 45 L ong-term changes in the number of breeding Mallards in Alberta.

The decline in SAB Mallards contrasts sharply with Mallard populations elsewhere. Breeding Mallard populations in the rest of the Canadian prairies as well as in the U.S. have shown little change over time or have actually increased (U. S. Fish and Wildlife Service 2010). Much of this decline can be attributed to the continuing loss of wetlands in SAB (Fig. 44). The effects of this habitat loss are obvious when local changes in the density of breeding Mallards in SAB are observed over time (Fig. 45). While annual changes in the distribution of breeding Mallards may influence Mallard numbers in the CB (as suggested by Rabenberg [1982]), the more recent decline in CB Mallards may ultimately be due to long-term declines in breeding populations especially those in SAB.

Figure 46 P ercent change predicted in duck productivity (1971–2001) as a result of wetland loss and upland habitat change.

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COLUMBIA BASIN

Figure 47 Change through time in the distribution of indicated breeding pairs of mallards (per square mile) in the Canadian prairies.

Carrying Capacity: Re-examining the Relationship Between Corn and Mallards Both Rabenberg (1982) and the current analysis relied on a single mid-winter count to index the size of the CB Mallard population. Detecting a statistical relationship between Mallards and corn may be difficult where a single survey provides the only measure of bird use across the entire fall-winter period (neither analysis found such a relationship). As a result, the relationship between Mallards and corn was evaluated by estimating Mallard use of the CB from fall through winter, not just early January. TRUEMET was used to evaluate the relationship between Mallard population energy demand in fall and winter and the total food energy supplied by corn for years between 4.46

1976 and 2004 (hereafter referred to as â&#x20AC;&#x153;year-specific analysesâ&#x20AC;?). For each year-specific analysis monthly waterfowl surveys and annual estimates of corn production were used. TRUEMET was also used to determine if corn production is sufficient to support Mallard population objectives established for the CB (Table 16). Model inputs and results are discussed below.

Model Inputs Waterfowl managers have typically divided the CB into the North, South, and East Subregions (Fig. 31). However, over 95% of Mallards counted in the mid-winter survey are traditionally been found in the North and South subregions. As a result the East subregion was excluded when evaluating the relationship between Mallard use of the CB and corn production. Data on waterfowl numbers and corn production were combined for the North and South Subregions in all TRUEMET analyses.

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COLUMBIA BASIN Time Periods Being Modeled Year-specific analyses of population energy demand vs. food energy supply were modeled on a monthly basis between 1976 and 2004. For 1976 to 1984 this included all months from October to February. After 1984 the model period was restricted to October–January because of data limitations. Population Objectives by Time Periods Monthly waterfowl surveys conducted by Washington Department of Fish & Wildlife were relied on for all year-specific analysis. Mallard counts from these surveys were used as monthly population inputs in TRUEMET after being corrected for visibility bias (Pearse et al. 2008). Monthly Mallard counts were available October to February 1976–1984, and October to January 1985– 2004. To determine if enough corn is now grown to meet Mallard needs the actual Mallard monthly population objectives for the CB were used (Table 16). Daily Bird Energy Requirements To estimate the daily energy requirement of Mallards in the CB the average body mass of adult male and female Mallards was obtained from Bellrose (1980) and a balanced sex ratio was assumed for the population. This resulted in an energy requirement estimate of 340 kcal / day. Habitat Availability and Biomass and Nutritional Quality of Foods Estimates of corn production used in all year-specific analyses were obtained from the USDA-NASS (2005). Corn fields in the CB were recently sampled to determine how much waste corn remained post-harvest. Approximately 40% of all corn acres in the CB are disked shortly after harvest; undisked fields averaged 269 lbs / acre of waste corn, while disked fields averaged 62 lbs / acre (Washington Department of Fish and Wildlife 2007). Based on a weighted average of disked and undisked fields, harvested corn fields provide an estimated 186 lbs / acre of waste grain biomass. A foraging threshold of 13 lbs / acre was subtracted (Baldassare and Bolen 1984) and an overall food density of 173 lbs / acre was used (. A TME value of 3.9 kcal / g was assumed for corn (Petrie et al. 1998).

since the 1970’s (Washington Department of Fish and Wildlife 2007), changes in waste grain biomass may have occurred. The amount of waste corn per acre is a function of standing crop biomass and harvest efficiency. Corn yields in the CB have nearly doubled since the early 1970’s (USDA-NASS 2005). However, these larger yields may have been offset somewhat by increases in harvest efficiency. Over the past thirty years the tendency in the CB has been to harvest corn at higher moisture content, a practice producing less waste grain because kernels are less likely to shatter, or dislodge from the cob (Washington Department of Fish and Wildlife 2007). Corn yields in the CB now average about 11,000 lbs/acre (USDA-NASS 2005). The current estimate 269 lbs/acre of waste grain suggests that harvest efficiency in the CB is about 98% and reflects the trend towards high moisture corn. During the mid-1970’s corn yields in the CB averaged about 5,600 lbs/acre (USDA-NASS 2005). If the amount of waste grain was similar to today’s estimate of 269 lbs / acre then harvest efficiency would have had to equal about 95% (.05 * 5600 = 280 lbs / acre). Harvest efficiency during the mid and late 1970’s was estimated at 94% (Rabenberg 1982). As a result, the recent 269 lbs / acre waste grain estimate was used in all year-specific analyses.

Model Results This section contains a subset of results that demonstrate how the relationship between energy demand and energy supply has changed over time. From 1976 through the early 1990’s the relationship between Mallard population energy demand and the food energy supplied by corn can be generally, but not sequentially, described as; 1) food energy moderately exceeded population energy demand through fall and winter, 2) food energy generally equaled population energy demand through fall and winter, and 3) food energy was less than population energy demand through fall and winter (Fig. 46). From the early 1990’s on the food energy supplied by corn appears to significantly exceed Mallard population energy needs (Fig. 47). These results suggest that from the mid-1970’s through the early 1990’s Mallard numbers in the CB were influenced by corn production. However, since the early 1990’s Mallard numbers appear to be well below the level that CB corn can support.

Year-specific analyses of the food energy provided by corn extended back to 1976. Although the fraction of corn fields disked in the CB does not appear to have changed

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COLUMBIA BASIN

Figure 48 F ood energy supply (red) vs. Mallard population energy demand (black) for years that represent the period 1976 â&#x20AC;&#x201C; 1992 in the Columbia Basin during winter.

Figure 49 F ood energy supply (red) vs. Mallard population energy demand (black) for years that represent the period 1993 to 2004 in the Columbia Basin during winter.

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COLUMBIA BASIN An estimated 78,000 acres of corn would be needed to support Mallard population objectives for the CB from October to February (Table 16), a figure that does not consider loss of corn that may result from decomposition or from consumption by species other than Mallards. Nor does it consider the spatial location of where corn is grown and how this may influence availability. Thus, it should be considered a minimum. The mid-winter or January population objective for Mallards in the CB is 561,747 birds (Table 15). This population objective was met four times between 1993 and 2010 after correcting for visibility bias. During this seventeen year period an average of 102,000 acres of corn was grown in the CB. Regression Analysis of Mallard Use-Days and Corn Production Monthly surveys conducted by Washington Department of Fish and Wildllife can be used to estimate the number of Mallard use- days that occur annually in the CB. One Mallard residing in the CB for a single day is equivalent to one Mallard use-day. Mallard use-days were calculated for all years between 1976 and 2004 for which data were available. For each year, Mallard use-days were determined by summing use-day totals for all months between October and January. Monthly use-days were determined by multiplying monthly survey results by days in the month. For example, 100,000 Mallards observed in the October survey equaled 3.1 million use-days for that month (100,000 * 31). The relationship between annual corn production and total Mallard use-days for that year was evaluated using simple linear regression. For all years between 1976 and 2004 there was a significant positive relationship between corn acres and total Mallard use-days between October and January (r 2 = 0.40; Fig. 48). This evaluation of carrying capacity suggested that from the mid-1970’s to the early 1990’s there was a fairly close relationship between Mallard population energy-demand and the food energy supplied by corn (Fig. 46). However, this relationship appeared to weaken from the early 1990’s on (Fig. 47). Similarly, a strong positive relationship between corn acres and Mallard use-days existed between 1976 and 1992 (r 2 = 0.63; Fig. 49), but no significant relationship existed thereafter (r 2 = 0.04; Fig. 50).

Figure 50 R elationship between annual Mallard use-days in the Columbia Basin during winter and the amount of corn planted the previous spring 1976–2004.

Figure 51 R elationship between annual Mallard use-days in the Columbia Basin during winter and the amount of corn planted the previous spring 1976–1992.

Figure 52 R elationship between annual Mallard use-days in the Columbia Basin during winter and the amount of corn planted the previous spring 1993–2004.

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COLUMBIA BASIN Wetland Carrying Capacity: Implications for Other Dabbling Duck Species

Habitat Availability and Biomass and Nutritional Quality of Foods

Although Mallards dominate the CB dabbling duck community, other species such as American Wigeon, Northern Pintail, and Green-winged Teal are present in modest numbers (Table 16). These species are considerably more dependent on wetland food supplies than are Mallards so TRUEMET was used to evaluate the carrying capacity of wetland habitats in the CB.

Most wetlands in the CB that provide food resources for Mallard, Northern Pintail, and Green-winged Teal are likely classified as palustrine emergent (Cowardin et al. 1979). Palustrine emergent wetlands in the North and South Subbasins total approximately 63,000 acres (Washington Department of Fish and Wildlife 2007). Approximately 5,000 of these acres are publicly managed wetlands and the remainder largely unmanaged (M. Moore, WADFW, pers. comm. Palustrine emergent wetlands were recently sampled in the CB to estimate the biomass of wetland plant seeds that are consumed by dabbling ducks. In unmanaged wetlands seed biomass was below the foraging threshold of 30 lbs/acre, indicating that most unmanaged wetlands provided little or no food for dabbling ducks (see discussion of foraging thresholds in the â&#x20AC;&#x153;Limiting Factors / Species-Habitat Modelsâ&#x20AC;? Biological Planning Section). In contrast, seed production in actively managed wetlands averaged about 180 lbs / acre. As a result, only managed habitats were included in this evaluation of wetland carrying capacity. TME of seeds produced in managed wetlands were assumed to average 2.5 kcal / gram (Checkett et al. 2002).

Model Inputs Time Periods Being Modeled The capacity of wetland habitats to meet the energetic needs of waterfowl in the CB was modeled on a monthly basis from October through February. Population Objectives by Time Period Monthly population objectives established for CB waterfowl were used to evaluate the carrying capacity of wetland habitats to meet nutritional needs of Mallard, Northern Pintail, and Green-winged Teal (Table 16). Mallards rely almost exclusively on corn from November onward. However, 25% of their diet is composed of wetland foods in October (Rabenberg 1982). Mallard consumption of wetland foods was accounted for by assuming that 25% of the October Mallard population meets its energy needs from wetlands but relies exclusively on agricultural foods thereafter. Northern Pintail and Green-winged Teal were assumed to meet 100% of their food energy needs from wetlands in all months. Although American Wigeon are the second most abundant dabbling duck in the CB they were not included in this analysis because most in the CB probably rely on SAV as their main food source. However, estimates of wetland food production in the CB are restricted to estimates of seed production (see below). Northern Shoveler and Gadwall also were excluded because of low numbers and their diets are usually dominated by foods other than seeds.

Model Results Managed wetlands in the CB appear able to meet 100% of Northern Pintail and Green-winged Teal food-energy needs between October and February when populations of these species are at NAWMP goals (Fig. 51).

Daily Bird Energy Requirements To estimate bird energy needs a weighted body mass was calculated from the contribution that Mallard, Northern Pintail, and Green-winged Teal made to the total dabbling duck population objectives used to evaluate wetland carrying capacity (Table 16). For each species the average body mass of adult male and female birds was used, assuming a balanced sex ratio (Bellrose 1980).

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Figure 53 F  ood energy supply (red) vs. population food energy demand (black) for Northern Pintail and Green-winged Teal in the Columbia Basin if both species rely exclusively on managed wetland food sources.

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COLUMBIA BASIN

Photo by Phillip Geist

Conservation Objectives for the CB Mallards dominate the CB dabbling duck objective and conservation objectives for this planning unit should strongly reflect the needs of this species. Rabenbergâ&#x20AC;&#x2122;s (1982) work and this recent evaluation of carrying capacity suggest that the factors regulating Mallard numbers have changed. From the early 1950â&#x20AC;&#x2122;s through the early 1990â&#x20AC;&#x2122;s corn production likely played a role in determining the size of the CB Mallard population. However, the strength of that relationship was probably influenced by the distribution of breeding Mallards the previous spring and by fall and winter weather though only Rabenberg (1982) was able to find statistical evidence of this. In drought years on the Canadian Prairies many Mallards are displaced northwest of the Alberta prairies where they are better positioned to migrate into the CB. During these years, large numbers of Mallards may have entered the CB and corn production may have determined the size of the Mallard population that could 4.51

be supported. In non-drought years on the Canadian Prairies, when fewer Mallards migrated into the CB, corn production was more likely to exceed bird needs and less likely to regulate Mallard numbers. Similarly, exceedingly cold temperatures or heavy snowfall may have limited Mallards numbers in some years regardless of how breeding birds were distributed or how much corn was grown. The scenario above suggests that corn production, weather events, and the size and distribution of the Mallard breeding population work together to influence Mallard numbers in the CB. It also requires that Mallard breeding populations that supply the CB with birds remain stable in the long-term, although these populations will obviously experience periodic changes in size and reproductive success. However, breeding populations that support wintering flocks in the CB have significantly declined (Fig. 43). Regardless of how breeding distribution may influence the number of Mallards that winter in the CB,

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COLUMBIA BASIN

Photo by Chris Bonsignore

there simply aren’t enough birds to achieve CB population levels that were observed in the early 1960’s, early 1980’s, and early 1990’s. This has reduced the probability that Mallard numbers are limited by corn. Consequently, Mallard numbers in the CB are now largely governed by external factors; specifically the decline of breeding populations in southern Alberta. The weakened relationship between corn and Mallard abundance suggests that any effort to increase waste grain supplies is unlikely to increase the number of birds wintering in the CB. However if corn production or waste grain availability was to be significantly reduced from current levels, corn supplies might again influence the upper limit of Mallard numbers in the CB. Most of the unmanaged wetlands that originated from irrigation projects in the CB now appear to provide little food at least for dabbling duck species that rely on seed production. While some management actions might be possible to increase the productivity of these unmanaged habitats, the actual number of dabbling ducks that rely on these habitats in the CB is low (Table 16). Mallards, which overwhelmingly dominate the dabbling duck community, appear to meet almost all their food energy needs from corn (Rabenberg 1982). Moreover, managed

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wetlands alone appear able to meet the food energy needs of species like Northern Pintail and Green-winged Teal (Fig. 51). The IWJV suggests that wetland conservation efforts taken on behalf of fall and wintering waterfowl should focus on existing managed wetlands. These habitats will require periodic enhancement or maintenance of existing management infrastructure to sustain high levels of food production. Maintaining the quality of these publicly managed habitats may also enhance hunting opportunities on these lands, and contribute to hunter retention objectives that are anticipated to be part of the 2012 NAWMP update. Some preliminary evidence suggests that large numbers of waterfowl may rely on the CB in spring, especially Northern Pintail (Fig. 38). Although the Yakima and Columbia Basin irrigation projects increased the amount of wetland habitat available to fall and wintering waterfowl, they also resulted in the loss of floodplain wetlands that were likely important for spring migrating waterfowl. Although the IWJV does not currently possess enough information to quantify conservation objectives for spring migration habitat in the CB, it is anticipated that wetland protection and restoration efforts on behalf of spring migrating waterfowl will be an emerging conservation priority in the near future.

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BREEDING WATERFOWL Wetland habitats in the Intermountain West have long been recognized as important breeding habitats for waterfowl. Indeed, establishment of the IWJV was in no small part due to concerns of population reductions in Redhead ducks in the Intermountain West. Crude indexes of annual breeding populations in the Intermountain West include 1.6â&#x20AC;&#x201C;2.1 million ducks, tens of thousands of Canada geese and the entire Rocky Mountain population of Trumpeter swans (â&#x2030;Ľ 2,000; USFWS 1995). Dabbling ducks are the most widespread and group of breeding waterfowl and Bellrose (1980) estimated approximately 5% of the breeding duck population in North America occupied the Intermountain West. Reliable estimates of breeding duck densities across the Intermountain West are challenging to obtain due to the heterogeneity of landscapes and variation in annual patterns of precipitation and wetland abundance. Over most areas, breeding duck densities are likely < 2 pairs/km2 but in some areas densities can exceed those observed in the Prairie Pothole Region (Gammonley 2004). High breeding pair densities are typically associated with managed wetland complexes within the Intermountain West. Some of the most important managed wetland complexes in the IWJV include the state, and federal owned lands (and in some cases privately managed wetlands) in the Great Salt Lake of Utah, the Malheur, Summer Lake Basins of Oregon, and the Klamath Basin of Oregon and California. At the Great Salt Lake, long term estimates suggest breeding densities of 75 ducks per square mile exist and as many as 100,000 ducklings have been produced annually (Sanderson 1980, Aldrich and Paul 2002). Duck production at Malheur once exceeded 100,000 ducklings but has declined significantly over the past two decades, due in large part to impacts of invasive carp on wetland quality. Also of note, the state managed Summer Lake area is also an important breeding waterfowl area in southern Oregon and has been estimated to produce 10,000 ducklings. Principal breeders in these regions include Gadwall, Mallard, Cinnamon Teal, and Redhead. Other managed areas of interest are the state and federally managed areas in the Lahontan Valley and Carson Sink of Nevada. The Stillwater National Wildlife Refuge and associated Wildlife Management Area have been estimated to produce 20,000 ducklings annually. Other managed wetland complexes across the Intermountain West provide important breeding habitat to waterfowl. For example, not only is Red Rock Lake, National Wildlife Refuge in southwest Montana a core breeding area for the Tri-State population of Trumpeter Swans, but is among the highest recorded breeding

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densities of Lesser Scaup in North America with over 30 pairs of lesser scaup per square mile recorded. Many unmanaged and privately owned habitats are important for breeding waterfowl in the Intermountain West as well. For example, many private lands in the Warner Valley of southeastern Oregon are managed for livestock production that includes mosaics of floodirrigated hay meadows, small grains, and sagebrush interspersed with alkali lakes. During wet years, the valley is heavily used by breeding Mallard, Gadwall, Cinnamon Teal, and Northern Pintail. In western Montana, northern Idaho, and western Wyoming, glacially carved valleys can have significant wetland footprints. Although the hydrology in most intermountain valleys has been modified to varying extents, breeding waterfowl are attracted to these regions and are common. Breeding densities are typically lower in these Intermountain valleys as compared to low elevation wetland complexes. The NAWMP and its Science Support Team have challenged Joint Ventures to develop spatially explicit conservation objectives and strategies for breeding waterfowl based on explicit linkages to demographic parameters. Although some of the earliest investigations into North American waterfowl biology began in the Intermountain West, the IWJV is currently challenged with appropriate information to inform our understanding of breeding waterfowl population dynamics across both temporal and multiple spatial scales. The IWJV will need to assemble estimates of breeding waterfowl abundance and/or densities, measures of expected key vital rates (e.g., nest success, duckling survival), and potential limiting factors associated with recruitment rates. In the absence of empirical understanding of relationships between limiting factors and waterfowl production, hypotheses regarding the functional relationship between these parameters may be needed. As such, the IWJV should initially develop conceptual models for breeding waterfowl in the Intermountain West to guide future development of biological planning and conservation strategies for breeding waterfowl. A critical first step will be to identify priority species for which future models are based. Consequently, the IWJV has identified a suite of priority breeding waterfowl species from which a focused approach (i.e., focal species) can be developed. This priority suite is derived from the NAWMP (2004) Regional Species Prioritization approach. Guidelines described in Table 17 were used to place species within one of three categories (Highest, High, Moderate) for each of the three primary Bird Conservation

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BREEDING WATERFOWL Regions (BCR), including the Great Basin, Northern Rockies, and Southern Rockies (referred to as Waterfowl Conservation Regions in NAWMP [2004]). Mallards were assigned to the highest category in each BCR due to their continental importance (Table 17) and significance related to Pacific Flyway harvest strategies through the Western Mallard Model. Regional information of species densities and population trends supplemented the criteria and rule sets listed in Table 17. Other supplemental information included assessments of a species uniqueness to the Intermountain West. For example, portions of the Intermountain West contain some of the highest breeding concentrations of Cinnamon Teal in North America. Thus, NAWMP regional priorities were used as guiding principles in establishing species priority suites.

BCR 9 GREAT BASIN

Lesser Scaup

High

High

Highest

Moderate

Mallard

High

Highest

Highest

Highest

Northern Pintail

High

High

Moderate

Moderate

American Wigeon

Mod High

Cinnamon Teal

Mod High

Highest

Highest

High

Redhead

Mod High

Highest

High

Moderate

Trumpeter Swan-RM

Mod High

Highest

Highest

High or Moderate Continental Concern

Barrowâ&#x20AC;&#x2122;s Goldeneye

Moderate

Moderate

Highest

High Continental Concern and Moderate BCR Responsibility

Bufflehead

Moderate

Moderate

Highest

Gadwall

Moderate

Moderate

Harlequin Duck

Moderate

High

Ringnecked Duck

Moderate

Moderate

Low

High

PRIORITY

CRITERIA/RULE High BCR Concern and High BCR Responsibility

HIGH

AND

SPECIES

BCR 10 BCR 16 NORTHERN SOUTHERN ROCKIES ROCKIES

Moderate

OR Moderate BCR Concern and High BCR Responsibility Moderate BCR Concern and Moderate BCR responsibility OR

MODERATE

IWJV PRIORITIZATION NAWMP CONTINENTAL PRIORITY

Table 17 C onservation priority categories and criteria used for waterfowl species in Bird Conservation Regions (BCR) within the IWJV.

HIGHEST

Table 18 P riority breeding waterfowl species suites for the three primary BCRs within the IWJV.

High Continental Concern and Low BCR Responsibility OR High BCR Responsibility and Low BCR Concern

Canada Goose-RM

From these criteria, 13 species were categorized into one of the three priority categories for the primary BCRs of the Intermountain West (Table 18). Based on this assessment the IWJV identifies Cinnamon Teal, Lesser Scaup, Mallard, Northern Pintail, Redhead, and the Rocky Mountain population of Trumpeter Swans as priority breeding waterfowl species to facilitate conservation actions within the Intermountain West. The IWJV will need to work closely with partners, particularly the Pacific Flyway Study Committees, USFWS Division of Migratory Birds, and State wildlife agencies, as the IWJV moves forward with science based conservation planning for breeding waterfowl in the Intermountain West.

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LITERATURE CITED Aldrich, T. W., and D. S. Paul. 2002. Avian ecology of Great Salt Lake. Pages 343-374 in Great Salt Lake: an Overview of Change (J. W. Gwynn, Ed.). Utah Department of Natural Resources and Utah Geological Survey Special Publication, Salt Lake City, Utah, USA. Arnow, T., and D. Stephens. 1990. Hydrologic characteristics of the Great Salt Lake, Utah: 1847-1986. U.S. Geological Survey Water-Supply Paper No. 2332, U. S. Government Printing Office, Washington, D.C, USA. Arzel, C., M. Guillemain, D. B. Gurdd, J. Elmberg, H. Fritz, A. Arnaud, C. Pinf, F. Bosca. 2007. Experimental functional response and inter-individual variation in foraging rate of teal (Anas crecca). Behavioural Processes 75:66–71. Baldassarre, G. A., and E. G. Bolen. 1984. Field-feeding ecology of waterfowl wintering on the southern high plains of Texas. Journal of Wildlife Management 48:63– 71. Ball, I. J., R. D. Bauer, K. Vermeer, and M. J. Rabenberg. Northwest riverine and Pacific coast. Pages 429-449 in L. M. Smith, R. L. Pederson, and R. M. Kaminski (eds.). Habitat management for migrating and wintering waterfowl in North America. Texas Tech University Press, Lubbock, Texas, USA. Bellrose, F. C., 1976. Ducks, Geese, and Swans of North America. Second ed. Stackpole Books, Harrisburg, Pennsylvania, USA. Bellrose, F. C. 1980. Ducks, Geese, and Swans of North America. Stackpole Books, Harrisburg, Pennsylvania, USA. Bedford, D., and A. Douglass. 2008. Changing properties of snowpack in the Great Salt Lake Basin, Western United States, from a 26-year SNOTEL record. Professional Geographer 60:374-386. Buller. R. J. 1975. Redistribution of waterfowl, influence of water, protection, and feed. International Waterfowl Symposium 1:143–154. Central Valley Joint Venture. 2006. Central Valley Joint Venture implementation plan – conserving bird habitat. U.S. Fish and Wildlife Service, Sacramento, California, USA. Conover, M. R., and J. L. Vest. 2009a. Selenium and mercury concentrations in California Gulls breeding on the Great Salt Lake, Utah, USA. Environmental Toxicology and Chemistry 28:324-329.

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Conover, M. R., and J. L. Vest. 2009b. Concentrations of selenium and mercury in eared grebes (Podiceps nigricollis) from Utah’s Great Salt Lake, USA. Environmental Toxicology and Chemistry 28:1319-1323 Conroy, M. J., G. R. Costanza, and D. B. Stotts. 1989. Winter survival of female American black ducks on the Atlantic Coast. Journal of Wildlife Management 53:99– 109. Downard, R. 2010. Keeping wetlands wet: the human hydrology of wetlands in the Bear River Basin. Thesis, Utah State University, Logan, Utah, USA. Duebbert, H. F. 1969. The ecology of Malheur Lake and management implications. U.S. Fish and Wildlife Service Refuge Leaflet 412. Dugger, B. D., M. J. Petrie, and D. Mauser. 2008. A bioenergetics approach to conservation planning for waterfowl at Lower Klamath and Tule Lake National Wildlife Refuge. U.S. Fish and Wildlife Service unpublished report. Ely, C. R., and D. G. Raveling. 1989. Body-composition and weight dynamics of wintering Greater White-fronted Geese. Journal of Wildlife Management 53:80–87. Engilis, A., Jr., and F. R. Reid. 1996. Challenges in wetland restoration of the western Great Basin. International Wader Studies 9:71–79. Fleskes, J. P., and D. S. Battaglia. 2004. Northern Pintail habitat use and waterfowl abundance during spring migration in southern Oregon-northeast California (SONEC): final report. USDI United States Geological Survey, Western Ecological Research Center, Sacramento, CA. Fleskes, J. P. and J. L. Yee. 2007. Waterfowl distribution and abundance during spring migration in southern Oregon and northeastern California. Western North American Naturalist 67:409–428. Fleskes, J. P., J. L. Lee, D. A. Skalos, J. D. Kohl, D. S. Battaglia, C. J. Gregory, and D. R. Thomas. 2013. Ecology of waterfowl and their habitats during spring migration in southern Oregon-northeastern California (SONEC): a major Pacific Flyway staging area. Sixth North American Duck Symposium, Memphis Tennessee. Poster presentation. Fretwell, S. D. 1972. Populations in a seasonal environment. Monograph in Population Biology 5. Princeton University Press, Princeton, New Jersey.

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LITERATURE CITED Galbreath, D. S. 1962. Waterfowl population increase in the Columbia Basin. Washington Game Bulletin 14:6–7. Gammonley, J. H. 2004. Wildlife of natural palustrine wetlands. Pages 130–153 in M. C. McKinstry, W. A. Hubert, and S. H. Anderson, eds. Wetland and Riparian Areas of the Intermountain West. University of Texas Press, Austin, Texas, USA. Gilmer, D. S., J. L. Yee, D. M. Mauser, and J. L. Hainline. 2004. Waterfowl migration on Klamath Basin National Wildlife Refuges 1953–2001. U.S. Geological Survey Biological Science Report No. USGS/BRD/BSR-20030004. Goss-Custard, J. D. R. A. Stillman, R. W. G. Caldow, A. D. West, and M. Guillemain. 2003. Carrying capacity in overwintering birds: when are spatial models needed? Journal of Applied Ecology 40:176–187. Hansen, H. A., and D. E. McKnight. 1964. Emigration of drought-displaced ducks to the Arctic. Transactions the North American Wildlife and Natural Resource Conference 29:119–127. Haukos, D. A., M. R. Miller, D. L. Orthmeyer, J. Y. Takekawa, J. P. Fleskes, M. L. Casazza, W. M. Perry, and J. A. Moon. Spring migration of northern pintails from Texas and New Mexico, USA. Waterbirds 29:127–241. Heitmeyer, M. E., and L. H. Fredrickson. 1981. Do wetland conditions in the Mississippi Delta hardwoods influence mallard recruitment? Transactions of the North American Wildlife and Natural Resources Conference 46:44–57. Johnson, A. M. 2007. Food abundance and energetic carrying capacity for wintering waterfowl in the Great Salt Lake wetlands. Thesis, Oregon State University, Corvallis, Oregon, USA. Kadlec, J. A., and L. M. Smith. 1989. The Great Basin marshes. Pages 451–474 in L. M. Smith, R. L. Pederson, and R. M. Kaminski (eds.). Habitat management for migrating and wintering waterfowl in North America. Texas Tech University Press, Lubbock, Texas, USA. Kaminski, R. M. and E. A. Gluesing. 1987. Density and habitat-related recruitment in mallards. Journal of Wildlife Management 51:141–148. Kapantais, K. N. D. Athearn, and J. Y. Takekawa. 2003. Waterfowl foods in agricultural fields of the Klamath Basin. Unpublished report. U.S. Geological Survey, Vallejo, CA.

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Kross, J., R. M. Kaminski, K. J. Reinecke, E. J. Penny, and A. T. Pearse. 2008. Moist-soil seed abundance in managed wetlands in the Mississippi Alluvial Valley. Journal of Wildlife Management 72:707-714. Lauckhart, J. B. 1961. Waterfowl population change. Proceedings of the Annual Conference of Western Association of State Game and Fish Commission. 40:157–160. Loving, B. L., K. M. Waddell, and C. W. Miller. 2002. Water and salt balance of Great Salt Lake, Utah, and simulation of water and salt movement through the causeway, 1963-98. Pages 143–166 in Great Salt Lake: an Overview of Change (J. W. Gwynn, Ed.). Utah Department of Natural Resources and Utah Geological Survey Special Publication, Salt Lake City, Utah, USA. Miller, M. R. 1986. Northern pintail body condition during wet and dry winters in the Sacramento Valley, California. Journal of Wildlife Management 50:57–64. Miller, M. R. and J. M. Eadie. 2006. The allometric relationship between resting metabolic rate and body mass in wild waterfowl (Anatidae) and an application to estimation of winter habitat requirements. Condor 108:166–177. Munro, R. E., and C. F. Kimball. 1982. Population ecology of the mallard: VII. Distribution and derivation of the harvest. U.S. Fish and Wildlife Service Resource Publication 147. National Ecological Assessment Team. 2006. Strategic Habitat Conservation. Final report of the national ecological assessment team. U.S. Fish and Wildlife Service and U.S. Geological Survey. http://www.fws.gov/ science/doc/SHC_FinalRpt.pdf Naylor, L. W. 2002. Evaluating moist-soil seed production and management in Central Valley wetlands to determine habitat needs for waterfowl. Thesis, University of California, Davis, California, USA. Naylor, L. W., J. M. Eadie, W. D. Smith, M. Eicholz, M J. Gray. 2005. A simple method to predict seed yield in moist-soil habitats. Wildlife Society Bulletin 33:13351341. Nolet, B. A., A. Gyimesi, and R. H. G. Klassen. 2006. Prediction of bird-day carrying capacity on a staging site: a test of depletion models. Journal of Animal Ecology 75:1285–1292.

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LITERATURE CITED North American Waterfowl Management Plan Assessment Steering Committee. 2007. North American Waterfowl Management Plan Continental Progress Assessment Final Report. http://www.fws.gov/birdhabitat/NAWMP/files/ FinalAssessmentReport.pdf North American Waterfowl Management Plan, Plan Committee. 2004. North American Waterfowl Management Plan 2004. Implementation Framework: Strengthening the Biological Foundation. Canadian Wildlife Service, U.S. Fish and Wildlife Service, Secretaria de Medio Ambiente y Recursos naturales, 106 pp. Pearse, A. T., P. D. Gerard, S. J. Dinsmore, R. M. Kaminski, and K. J. Reinecke. 2008. Estimation and correction of visibility bias in aerial surveys of wintering ducks. Journal of Wildlife Management 72:808–813 Petrie, M. J., R. D. Drobney, and D. A. Graber. 1998. True metabolizable energy estimates of Canada goose foods. Journal of Wildlife Management 62:1147–1152. Petrie, M. J., M. G. Brasher, G. J. Soulliere, John M. Tirpak, D. B. Pool, and R. R. Reker. 2011. Guidelines for establishing Joint Venture waterfowl population abundance objectives. North American Waterfowl Management Plan Science Support Team Technical Report No. 20111. http://www.fws.gov/birdhabitat/NAWMP/NSST/files/ GuidelinesforEstablishingJVPopulationObjectives.pdf Pospahala, R. S., D. R. Anderson, and C. J. Henny. 1974. Population ecology of the mallard: II. Breeding habitat conditions, size of the breeding populations, and production indices. U.S. Fish and Wildlife Service Resource Publication 115. Rabenberg, M. J. 1982. Ecology and population dynamics of mallards wintering in the Columbia Basin. M.S. Thesis, University of Montana, Missoula. 135 pp.

Raveling, D. G., and M. E. Heitmeyer. 1989. Relationships of population size and recruitment of pintails to habitat conditions and harvest. Journal of Wildlife Management 53:1088–1103. Reinecke, K. J., R. M. Kaminski, D. J. Moorhead, J. D. Hodges, and J. R. Nassar. Mississippi Alluvial Valley. Pages 203–247 in L. M. Smith, R. L. Pederson, and R. M. Kaminski (eds.). Habitat management for migrating and wintering waterfowl in North America. Texas Tech University Press, Lubbock, Texas, USA. Stafford, J. D., R. M. Kaminski, K. J. Reinecke, and S. W. Manley. 2006. Waste rice for waterfowl in the Mississippi Alluvial Valley. Journal of Wildlife Management 70:61–69. Stephens, D. W. 1990. Changes in lake levels, salinity and the biological community of Great Salt Lake (Utah, USA), 1847–1987. Hydrobiologia 197:139-146. United States Department of Agriculture, National Agricultural Statistics Service. Retrieved May 2005, from http://www.nass.usda. gov/Data_and_Statistics/Quick_Stats/index.asp Utah Department of Natural Resources. 2013. Final Great Salt Lake comprehensive management plan and record of decision. Utah Department of Natural Resources, Division of Forestry, Fire, and State Lands, Salt Lake City, Utah, Usa. http://www.ffsl.utah.gov/sovlands/ greatsaltlake/2010Plan/OnlineGSL-CMPandRODMarch2013.pdf Vest, J. L. and M. R. Conover. 2011. Food habits of wintering waterfowl on the Great Salt Lake, Utah. Waterbirds 34:40–50. Washington Department of Fish and Wildlife. 2007. Columbia Basin Waterfowl Management Plan, 2007. Olympia, Washington. Unpublished report.

Raveling, D. G. 1979. The annual energy cycle of the cackling Canada goose. Pages 81–93 in R. L. Jarvis and J. C. Bartonek, editors. Management and biology of the Pacific flyway geese: a symposium. Oregon State University Book Stores, Inc., Corvallis, Oregon, USA.

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APPENDIX A. WATERFOWL SCIENCE TEAM MEMBERS • Tom Aldrich, Utah Division of Wildlife Resources • Brad Bales, Oregon Department of Fish and Wildlife • Brad Bortner, U.S. Fish and Wildlife Service • Bruce Dugger, Oregon State University • Joseph Fleskes, U.S. Geological Survey •D  on Kraege, Washington Department of Fish and Wildlife • Craig Mortimore, Nevada Department of Wildlife • Mike Rabe, Arizona Game & Fish Department •D  an Yparraguirre, California Department of Fish and Game

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Cha pte r Five

Shorebirds

Pr incipa l Autho r s: Sue T homa s, B r ad A ndre s, a nd Josh Ve st

Photo by Scot t Root


Inside this Chapter

Shorebird S h o r eStrategy birds

Introduction........................................................................................................................... 5.3 •

Guiding Documents.......................................................................................................... 5.3

Partnership Guidance....................................................................................................... 5.4

Planning Approach: Key-Site Strategy, Bioenergetics Modeling.. ........................................ 5.4

Description of the Region.. ................................................................................................ 5.4

An Introduction to Biological Planning for Shorebirds.......................................................... 5.5 Shorebirds of the Intermountain West.. ................................................................................. 5.6 Shorebird Habitat Types........................................................................................................ 5.9 Population Status & Trends................................................................................................. 5.11 Threats & Limiting Factors.................................................................................................. 5.13 •

Water Quantity and Quality.. ............................................................................................ 5.13

Habitat Loss or Degradation.. .......................................................................................... 5.13

Agriculture.. .................................................................................................................... 5.13

Rural Urbanization.......................................................................................................... 5.14

Invasive Species............................................................................................................. 5.14

Contaminants and Disease Outbreaks............................................................................. 5.15

Other Anthropogenic Factors.......................................................................................... 5.15

Climate Change.............................................................................................................. 5.15

Population Estimates & Objectives..................................................................................... 5.16 •

Population Estimates...................................................................................................... 5.16

Assumptions and Limitations of Data.. ............................................................................. 5.16

Regional Population Objectives....................................................................................... 5.16

Key Sites for Shorebird Conservation................................................................................. 5.19 •

The Great Salt Lake Key Site Conservation Strategy........................................................ 5.21

Blanca Wetlands Shorebird Habitat Strategy.. .................................................................. 5.22

Breeding Shorebird Focal Species...................................................................................... 5.22 •

Focal Species Profiles.. ................................................................................................... 5.23

Literature Cited................................................................................................................... 5.25 Appendix A. Shorebird Science Team Members.................................................................. 5.27 Appendix B. Status of Shorebird Species.. .......................................................................... 5.28 Appendix C. Common & Scientific Names of Shorebird Species Listed in this Document.. ..................................................................................................... 5.30

5.2

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INTRODUCTION Joint Ventures have collectively embraced all-bird conservation and have been tasked with improving the science driving species and habitat conservation actions through the use of integrated biological planning, conservation design, and delivery as well as addressing monitoring and research. One goal of this task is to link species-specific population objectives to explicit habitat targets for priority bird species in the Joint Venture. To meet that goal, a team of biologists focused on shorebird conservation in the Intermountain West (Appendix I) was convened to develop and guide the process. This Shorebird Science Team (SST) established focal species, developed population estimates and objectives, established focal species, and identified key sites.

Guiding Documents This Shorebird Conservation Strategy builds upon the U.S. Shorebird Conservation Plan (USSCP; Brown et al. 2000) and the 2005 Intermountain West Joint Venture (IWJV) Coordinated Bird Conservation Plan [a.k.a. 2005 IWJV Implementation Plan (IWJV 2005)]. It is intended to provide a source of quantitative population objectives for shorebirds which have not previously been available that will facilitate the development of landscape level conservation planning for shorebirds in the Intermountain West that can be linked to continental goals. This effort expands on work accomplished in the Intermountain West Regional Shorebird Conservation Plan (IWRSCP; Oring et al. 2000). The 2005 IWJV Implementation Plan recognized the potential value of wetland conservation for all bird species. Therefore, the plan coordinated the needs of all birds in the Intermountain West through planning focal points set by key geographies where priority birds and priority habitats intersect. These areas were called Bird Habitat Conservation Areas (BHCA). The plan identifies, describes, and ranks priority habitats. Furthermore, it provided habitat goals and quantifiable objectives for priority habitats by state. However, while partners use existing information, including the IWRSCP, to focus shorebird conservation efforts on priority habitats, sites and species, it fell short of developing habitat objectives specifically for shorebirds. This update will build on the strengths of the 2005 Implementation Plan’s habitat conservation actions by providing information on specific habitat characteristics important to shorebirds and species-specific population and habitat objectives. The USSCP provides continental population estimates and objectives, an assessment of conservation concern by

5.3

species, and step-down plans at the regional level. The IWRSCP includes the entirety of the IWJV and identifies the most important issues facing shorebird conservation in the Intermountain West, such as competition for water (Oring et al. 2000). Finding ample, high quality fresh water will be the greatest shorebird habitat conservation challenge in this area. The IWRSCP plan addresses this and other issues through five goals and associated objectives and strategies. The IWRSCP also identifies important shorebird habitats in the region and provides site-specific information on 11 key sites. The habitat types and key sites identified in the IWRSCP are the focal points of this strategy. Threats and conservation actions are identified by the region and key sites. The plan identifies and prioritizes breeding and migrant shorebird species, provides data on distribution and abundance by Bird Conservation Region (BCR), and identifies important habitat types. However it stops short at providing population or habitat objectives. Since completion of the IWRSCP, limited progress has been made in implementing IWRSCP habitat objectives. Thus, the goal of this strategy is to further develop and implement the objectives listed in the IWRSCP, synthesized and updated herein. • Work cooperatively with private, state, and federal interests in developing site-specific management plans for key shorebird habitats in the region. • Coordinate site-specific management activities between sites to ensure that shorebird needs are met within the region. • Identify habitats by BCR and state that are important to production of priority species dependent on these habitats (e.g., Long-billed Curlew, Wilson’s Phalarope). • Integrate restoration and enhancement action for shorebirds into existing or new wetland management plans in the region. • Facilitate development and implementation of management strategies that will conserve, protect, and enhance large blocks of upland habitat adjacent to strategically important saline and freshwater wetlands • Catalyze wetlands conservation by JV partners to address the needs of shorebirds as described in this Strategy through the North American Wetlands Conservation Act, Wetlands Reserve Program, and other conservation programs. • Develop strategies that will help protect water quality and ensure sufficient water supplies for important shorebird habitats.

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AN INTRODUCTION TO BIOLOGICAL PLANNING FOR SHOREBIRDS Partnership Guidance With the development of population estimates and objectives for the BCRs within the Intermountain West and identification of important sites, partners will have information not previously available to develop and assess conservation measures for shorebirds and their habitats (e.g., development of targeted Farm Bill or NAWCA projects). In addition, this information should also be useful in the development and ranking of NAWCA Small and Standard Grants by providing a framework from which to evaluate the relevance of sites throughout the Intermountain West and habitat objectives that are meaningful in the context of important sites and species. Development of habitat objectives will be an ongoing, iterative process. While they have been developed at a subset of sites, the intention for the JV partnership is to continue development of site-based conservation strategies for additional key sites in the future following the framework established for the current sites. This Strategy is intended to be relevant for approximately 15 years, at which time the population and habitat objectives will be reassessed if new information is available.

Planning Approach: Key-Site Strategy, Bioenergetics Modeling The IWJV’s SST recognized early in this planning that bioenergetics modeling would greatly advance shorebird conservation in the Intermountain West by establishing defensible shorebird habitat objectives. This approach has been used effectively by Joint Ventures across the Nation to identify the food energy resources needed to support non-breeding waterfowl and characterize the capability of the landscape to provide those resources. This modeling process informs habitat protection, restoration, and management by defining the amount of various habitats needed to “keep the table set” for waterfowl at continental goal populations. The SST determined that bioenergetics modeling for shorebirds would be most appropriately conducted at the “key site” scale. The SST made the decision to employ bioenergetics modeling for shorebirds in two key sites – the Great Salt Lake and the Blanca Wetlands Habitat Area. These sites were chosen to pilot the bioenergetics modeling process in the Intermountain West and serve as a prototype for similar modeling projects in the other 16 shorebird key

5.4

sites in the future. The sites were chosen because they represent the extremes in size and complexity of the key sites described in this Strategy. The Great Salt Lake is the largest, most important, and most complex of the shorebird key sites. The Blanca Wetlands is a small key site owned and managed by a single landowner, perhaps the least complex of the shorebird key sites. As such, this approach allowed the IWJV to test the bioenergetics modeling approach for shorebirds at both ends of the spectrum, a valuable step in determining appropriate population-habitat modeling approaches for migrating shorebirds in the Intermountain West. This approach was successfully employed and resulted in two sub-chapters of the 2013 IWJV Implementation Plan – The Great Salt Lake Shorebird Key Site Conservation Strategy (Chapter 5.1) and the Blanca Wetlands Habitat Strategy (Chapter 5.2). These sub-chapters are summarized within this Strategy but are presented as stand-alone documents within the context of the overall 2013 Implementation Plan. These documents will help habitat managers and members of the JV partnership carry out strategic shorebird habitat conservation in these landscapes – doing the right things in the right places – while providing a roadmap for the JV partnership to conduct shorebird conservation planning in other key sites in the future.

Description of the Region With 486 million acres spread over 11 western states, the IWJV is one of the largest JVs in North America. The IWJV boundary falls within two major flyways – the Pacific and Central Flyways, the majority of 3 BCRs – Great Basin (BCR 9), Northern Rockies (BCR 10), Southern Rockies/Colorado Plateau (BCR 16), and small portions of 7 BCRs – Sonoran and Mojave Deserts (BCR 33), Sierra Madre Occidental (BCR 34), Chihuahuan Desert (BCR 35), Pacific Rainforest (BCR 5) and Sierra Nevada (BCR 15), Badlands and Prairies (BCR 17) and Shortgrass Prairie (BCR 18; Fig. 1). Because they encompass such a small area within the IWJV boundary, we will not address BCRs 5, 15, 17 and 18 in this Strategy. These BCRs have been addressed within implementation plans developed by the Pacific Coast, Central Valley, Northern Great Plains and Playa Lakes Joint Ventures respectively.

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AN INTRODUCTION TO BIOLOGICAL PLANNING FOR SHOREBIRDS

Photo by USF WS

Figure 1 B  ird Conservation Regions occurring within the Intermountain West Joint Venture. 5 = Northern Pacific Rainforest, 9 = Great Basin, 10 = Northern Rockies, 15 = Sierra Nevada, 16 = Sierra Nevada, 17 = Badlands and Prairies, 18 = Shortgrass Prairie, 33 = Sonoran and Mojave Deserts, 34 = Sierra Madre Occidental, 35 = Chihuahuan Desert.

5.5

As a result of its vast size, the Intermountain West encompasses some of the most diverse habitats of any Joint Venture due, in part, to significant ranges in degrees of latitude, elevation (â&#x20AC;&#x201C;285 to >14,000 feet), and climate. Important shorebird habitats identified by the IWRSCP include: large saline lakes; marshes and lake/ marsh complex; upland areas near wetlands; agricultural fields; ephemeral wetlands and playas; impoundments; and riparian areas (Oring et al. 2000). The vast majority of shorebird habitat in the Intermountain West exists as inland oases of discrete wetlands separated by over 600 mountain ranges and seven of the largest deserts in North America. Four Western Hemisphere Shorebird Reserve Network (WHSRN) sites are located in the region, including: Great Salt Lake, UT (site of Hemispheric Importance); Lahontan Valley, NV (Hemispheric); Mono Lake, CA (International); and Springfield Bottoms/ American Falls Reservoir, ID (Regional). Eight additional sites meet or exceed qualification for designation as WHSRN Sites of Regional Importance, including: Harney Basin, Lake Abert, Summer Lake, Warner Basin, Klamath Basin in OR; Goose Lake in OR/CA; Honey Lake in CA; and San Luis Valley in CO.

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SHOREBIRDS OF THE INTERMOUNTAIN WEST

Photo by Phil Douglass

The Intermountain West supports approximately one million breeding shorebirds and several million passage birds of 34 species (Oring et.al. 2000). The majority of North America’s populations of Snowy Plover, American Avocet, Black-necked Stilt, and Long-billed Curlew breed in the area (Appendix II). Scientific names of shorebird species referenced in this strategy are found in Appendix III. The Intermountain West is most important to shorebirds during migration. Approximately 90% of the global population of Wilson’s Phalaropes, and very large numbers of Red-necked Phalaropes, Long-billed

5.6

Dowitchers, Western Sandpipers, and Marbled Godwits stage or stopover in the area (Oring et al. 2000). Due to its vast size, the Intermountain West supports thousands of wintering shorebirds as well. Table 1 provides an indication of seasonal importance of the BCRs in the Intermountain West by species. This information can help to guide conservation actions within the most important BCRs by the appropriate season. For instance, habitat conservation measures in BCRs 9 and 10 would help meet population and habitat objectives for breeding Wilson’s Phalaropes in the Intermountain West.

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SHOREBIRDS OF THE INTERMOUNTAIN WEST Table 1 S  easonal occurrence of shorebird species in the Intermountain West and each BCR within the IWJV. Table adapted from Oring et al. (2000). Codes: M = Migrant, W = Wintering, B = Breeding. B,M,W = high concentrations, region extremely important to the species relative to the majority of other regions. B,M,W = common or locally abundant; region important to the species relative to other regions. b,m,w = uncommon to rare; region within species range but occurs in low abundance relative to other regions. BIRD CONSERVATION REGION

SPECIES

ENTIRE IWJV

9

10

16

33

Black-bellied Plover

M,W

M

M

M

M,W

Snowy Plover

M,W,B

B,M

B,M

B,W

Semipalmated Plover

M,w

M

m

M,w

M,w

Killdeer

M,W,B

M,B

M,B

M,W,B

M,W,B

Mountain Plover

m,W,B

m,B

m,B

W

W

Black-necked Stilt

M,W,B

m,B

M

M,B

M,W,B

m

American Avocet

M,W,B

M,B

M,B

M,B

M,W,B

m

Greater Yellowlegs

M,W

M

M

M

m,w

m,w

Lesser Yellowlegs

M,w

M

M

M

m,w

m

Solitary Sandpiper

M

M

m

M

Willet

M,W,B

M,B

M,B

M

M,W

Spotted Sandpiper

M,W,B

m,B

M,B

M,B

m,w

Upland Sandpiper

m,b

B

m,b

M

Whimbrel

M

M

m

M

M

m

Long-billed Curlew

M,W,B

M,B

M,B

M,b

M,W

m

Marbled Godwit

M,W,b

M

M,b

M

M,W

Red Knot

M

M

m

M

M

Sanderling

M

M

m

M

m,w

Semipalmated Sandpiper

M

M

m

M

Western Sandpiper

M,W

M,W

M

M

M,W

m

Least Sandpiper

M,W

M

M

M,W

M,W

m

Baird's Sandpiper

M

M

M

M

m

Pectoral Sandpiper

M

M

M

M

Dunlin

M,W

M

M

M

m,w

Stilt Sandpiper

M

M

m,W

Short-billed Dowitcher

M

M

m

Long-billed Dowitcher

M,W

M

M

M

M,W

Wilsonâ&#x20AC;&#x2122;s Snipe

M,W,B

m,W,B

m,W,B

M,W,B

m,w

Wilson's Phalarope

M,B

M,B

M,B

M,b

M

Red-necked Phalarope

M

M

M

M

M

5.7

34

35

b

m,b

m,b

m

m

m m

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M


SHOREBIRDS OF THE INTERMOUNTAIN WEST The USSCP provides Area of Importance Scores for each BCR for populations of shorebirds in North America (Table 2). These scores signify the relative importance of each BCR to a species throughout their annual life cycle. They also reflect perceived importance of management

and protection activities relative to other regions. When combined with the information in Table 1 they can provide an excellent means to direct conservation actions at broad scales within the most important BCRs during the most appropriate seasons.

Table 2 R  egional and Bird Conservation Region (BCR) Area of Importance Scores (AI) for shorebirds in the Intermountain West. Table shows only those species with critical to common occurrence within the IWJV and BCRs adapted from Bird Conservation Region Area Importance Socres at www.fws.gov/shorebirdplan/RegionalShorebird.htm BIRD CONSERVATION REGION SPECIES

IWJV

9

10

16

33

34

35

Black-bellied Plover

4

4

4

4

4

1

1

Snowy Plover

5

5

1

4

5

2

3

Semipalmated Plover

4

3

3

4

4

1

2

Killdeer

4

4

4

4

4

3

3

Mountain Plover

5

1

4

4

4

2

2

Black-necked Stilt

5

5

4

5

3

2

3

American Avocet

5

5

4

4

4

1

3

Greater Yellowlegs

4

3

4

4

4

2

3

Lesser Yellowlegs

4

3

4

4

3

2

3

Solitary Sandpiper

3

3

3

3

1

1

3

Willet

5

5

5

4

3

1

1

Spotted Sandpiper

5

4

4

4

3

3

3

Upland Sandpiper

3

3

3

3

1

1

3

Whimbrel

5

3

3

3

5

1

3

Long-billed Curlew

5

5

5

4

4

2

3

Marbled Godwit

4

4

4

4

4

1

1

Red Knot

3

3

3

3

4

1

1

Sanderling

3

3

3

3

3

1

1

Semipalmated Sandpiper

3

3

3

3

1

1

1

Western Sandpiper

5

5

3

3

5

2

3

Least Sandpiper

5

4

3

4

4

2

3

Baird's Sandpiper

4

4

3

4

3

1

1

Pectoral Sandpiper

3

3

3

3

1

1

1

Dunlin

4

3

3

4

3

1

1

Stilt Sandpiper

3

1

1

3

4

1

2

Short-billed Dowitcher

2

1

1

1

2

1

1

Long-billed Dowitcher

5

5

5

5

4

2

2

Wilson's Snipe

4

4

4

4

3

2

2

Wilson's Phalarope

5

5

5

5

4

2

3

Red-necked Phalarope

5

5

5

5

4

1

1

5.8

C o d e s: 5 = T h e a r e a i s c r i t i c a l for suppor ting hemispheric p o p u l a t i o n s o f t h e s p e c i e s; 4 = T h e a r e a i s i m p o r t a n t to suppor ting hemispheric or r e g i o n a l p o p u l a t i o n s; 3 = T h e area is within the range of the species and the species occurs regularly within the region but in l ow a b u n d a n c e; 2 = T h e a r e a i s within the range, but in general, m a n a g e m e n t i s n o t wa r r a n te d f o r t h i s s p e c i e s; 1 = D o e s n o t o c c u r in the area

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SHOREBIRD HABITAT TYPES Most shorebirds forage in water depths up to 7 inches, depending on bill length; however, as with all species groups, exceptions can be found. The Wilson’s Phalarope forages in open water taking its prey from the top of the water column. Vegetation density is also an important factor in habitat preferences as most shorebirds prefer short, sparse vegetation. The majority of species will select foraging habitats with less than 25% vegetative cover (Helmers 1992). Wilson’s Snipe is an exception to the rule in their preference for dense sedge stanch. The following habitat types follow those described in the IWRSCP.

Large Saline and Alkaline Lakes These are typically large terminal lakes that have a high salt concentration, at times greater than the concentration of seawater. Alkali lakes are also included in this category and differ from salt lakes due to a higher concentration of a basic ionic salt. Large saline lakes differ from playas in that they contain water year-round. Large saline lakes are considered lacustrine habitats according to the National Wetlands Inventory classification system. The most important shorebird sites in the Intermountain West are located adjacent to large saline lakes. In fact, one of the most important sites for shorebirds in North America, Great Salt Lake, has been identified by WHSRN as a site of Hemispheric Importance (supporting at least 500,000 shorebirds annually). During wet years, saline lakes and adjacent wetlands in the Lahontan Valley of Nevada, also reach Hemispheric Importance. Other large saline lakes in the region surpass the annual requirement of 100,000 and 20,000 shorebirds for status as a WHSRN site of International or Regional Importance, respectively. These include: Lake Abert and Summer Lake, Oregon; Mono Lake, California (International significance), Honey and Alkali Lakes, California; and Goose Lake, California/ Oregon (Regional significance). These sites have been identified as key sites for conservation action within this plan. Thirty percent (5,510 individuals) of the current estimated population of inland-breeding Snowy Plovers occur at Great Salt Lake (Thomas 2005, Morrison et al. 2006). Saline lakes are also important breeding sites for American Avocets; approximately half of the global population breeds in the Intermountain West, predominantly on saline lake habitat. Black-necked Stilts, Long-billed Curlews, Wilson’s Phalaropes, Spotted Sandpipers, Killdeers, Willets and Wilson’s Snipe also nest in saline lake habitat. Saline lakes are also important to passage American Avocets and Wilson’s and Rednecked Phalaropes. In fact, over 50% of the global 5.9

population of Wilson’s Phalaropes stage at three of the most prominent saline lakes in the Intermountain West: Great Salt Lake, Lake Abert, and Mono Lake (Colwell and Jehl 1994). Black-necked Stilts, Marbled Godwits, and Western Sandpipers also use saline lakes in high concentrations on migration.

Marshes and Lake/Marsh Complexes Marshes are typically shallow, low-lying areas (near the water table), with fluctuating water levels and salinities. They are also referred to as wet meadow, submerged aquatic beds, or emergent wetlands. They can be predominantly fresh, brackish, or saline. They support an abundance of grasses, rushes, reeds, and sedges and differ from grasslands in having soils that are wet in most years. This habitat type can be classified as palustrine open water, emergent, aquatic bed, unconsolidated bottom, or unconsolidated shore according to NWI. Large freshwater marshes of importance to a variety of shorebirds are associated with most of the major saline lakes and playas in the Intermountain West, such as the Bear River marsh complex adjacent to Great Salt Lake, Utah. Examples of freshwater marshes not associated with saline lakes/playas include the Warner Valley, Oregon, and Lower Klamath NWR, California. A high proportion of the world’s American Avocets and Black-necked Stilts breed in the wetlands of the Intermountain West, especially in the saline lake associated marshes of the Great Basin. Moderate numbers of Wilson’s Phalaropes and Willets and lesser numbers of other species also breed in these marshes. Large numbers of Long-billed Dowitchers, Calidris sandpipers, primarily Western and Least Sandpipers, and lesser numbers of many species, stop over at Great Basin marshes on migration (Oring et al. 2000).

Ephemeral Wetlands/Playas Small ephemeral wetlands, playas, and salt flats abound in the Intermountain West. They are typically shallow depressions lined with a salt or alkali crust limiting vegetation growth along the shore. These depressions fill with water seasonally, intermittently, or temporarily depending on the depth of the water table or amount of precipitation. Ephemeral wetlands or playas can be classified as palustrine, particularly in association with palustrine unconsolidated bottom, open water, or unconsolidated shore according to NWI. In wet years, ephemeral wetlands can support high numbers of shorebirds, especially breeding American Avocets and migrant Western Sandpipers (Neel and Henry 1997). However, in any given year and area, this habitat type may be dry and will not support shorebirds unless a

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SHOREBIRD HABITAT TYPES steady seep or spring is available. Examples of important playas in the Intermountain West include old salt lake beds such as Winnemucca Lake, Nevada, that rarely holds water in any but the wettest years.

high concentration of Long-billed Curlews during the breeding season. Although waste grain is rarely consumed by shorebirds, the invertebrates in or on the soil surface can be a primary food source.

Upland/Grasslands

Manmade Impoundments

Primary upland/grassland types include bunchgrasses, short and mixed grass prairie, and grassland shrub types in the southwest. Dry grasslands are important to nesting Long-billed Curlews, Mountain Plovers, Upland Sandpipers, and Willets. This habitat type is particularly important for a variety of grassland nesting shorebirds such as the Willet and Long-billed Curlew when adjacent to wetlands and riparian areas. Mountain Plovers nest in arid upland areas with low vegetation. An isolated population of Upland Sandpipers breeds in short to mid height grasslands and forages in shorter stature vegetation in eastern Oregon and possibly still in eastern Washington, northern Idaho, and western Montana (Paulson 1993).

This habitat type includes any man-made water storage basins such as reservoirs, salt evaporation ponds, or other types of water catchment basins. The levees that surround the water are often used during the nesting season by Snowy Plovers, American Avocets, and Black-necked Stilts, Long-billed Dowitchers and Western Sandpipers use this habitat type on migration. Suitable water levels (≤ 7 inches for long legged shorebirds) are necessary to support shorebirds in this habitat. The American Falls Reservoir in southeastern Idaho is an example of an important manmade impoundment in the Intermountain West. This site along with adjacent Springfield Bottoms wetlands has been designated as a WHSRN site of Regional Importance supporting up to 20,000 shorebirds annually.

Agricultural Fields Agriculture has become an important source of habitat for shorebirds particularly if near a stable source of fresh water for chick rearing. Hay and grain fields, pastures, and dairy farms are used by shorebird species at different times of the year. Many species, such as Longbilled Curlew and Killdeer flock in flooded or recently dewatered fields during migration. Killdeer, Wilson’s Phalarope, and Long-billed Curlew nest in these habitats, particularly near freshwater inflows. The hay fields and flooded pastures of the Ruby Valley, Nevada support a

Riparian Areas Sand bars and mud flats along rivers and streams support small numbers of shorebirds annually. They are equivalent to NWI riverine classification. These areas are particularly important to breeding Spotted Sandpipers. Small numbers of American Avocets, Black-necked Stilts, Least Sandpipers, and Wilson’s Phalaropes use riparian habitats during migration stopover.

P h o t o b y J o s h Ve s t

5.10

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POPULATION STATUS & TRENDS National, regional, and state conservation status of common shorebirds in the Intermountain West is provided in Table 3. All shorebirds listed under the 2008 U. S. Fish and Wildlife Service’s (USFWS) Birds of Conservation Concern list (USFWS 2008), which updates the 2002 Birds of Management Concern List and NAWCA Priority Bird Species list (Online at http://www.nabci-us.org/aboutnabci/nawcaspp.pdf), are included in Table 3. Seventeen species of shorebirds have been identified by state fish and wildlife agencies as Species of Greatest Conservation Need in State Wildlife Action Plans (Table 3). Table 3 N  ational, Regional, and State conservation status of shorebird species in the Intermountain West. STATE WILDLIFE ACTION PLAN SPECIES OF GREATEST CONSERVATION NEED COMMON NAME

CC2

IA1

Black-bellied Plover

3

4

Snowy Plover

5

5

Semipalmated Plover

2

4

Killdeer

3

4

Mountain Plover

5

5

Black-necked Stilt

2

5

American Avocet

3

5

Greater Yellowlegs

3

4

Lesser Yellowlegs

3

4

Solitary Sandpiper

4

3

Willet

3

5

Spotted Sandpiper

2

5

Upland Sandpiper

4

3

Whimbrel

4

5

Long-billed Curlew

5

5

Marbled Godwit

4

4

Red Knot

4

3

Sanderling

4

3

Semipalmated Sandpiper

3

3

Western Sandpiper

4

5

Least Sandpiper

3

5

Baird's Sandpiper

2

4

Pectoral Sandpiper

2

3

Dunlin

3

4

Stilt Sandpiper

3

3

Short-billed Dowitcher

4

3

Long-billed Dowitcher

2

5

Wilson's Snipe

3

4

Wilson’s Phalarope

4

5

Red-necked Phalarope

3

5

5.11

AZ

CA

CO

ID

MT

NM

NV

OR

UT

WA

WY

√ √

√ √

√ √

√ √

Conservation Categories from US Shorebird Conservation Plan. 5 = Highly Imperiled, 4 = Species of High Concern, 3 = Species of Moderate Concern, 2 = Species of Low Concern, 1 = Species Not at Risk. 1

From Bird Conservation Region Area Importance Scores at www.fws.gov/shorebirdplan/ RegionalShorebird.htm 2

√ √

Codes: 5 = The area is critical for supporting hemispheric populations of the species; 4 = The area is important to supporting hemispheric or regional populations; 3 = The area is within the range of the species and it occurs regularly within the region but in low abundance; 2 = The area is within the species range, but in general, management is not warranted for this species; 1 = Does not occur in the area.

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POPULATION STATUS & TRENDS Morrison et al. (2006) provided summary of general population trends for species or sub-species of shorebirds in North America. These trends are provided in Table 4 to provide further context of shorebirds in the Intermountain West relative to continental trends. Table 4 N  orth American population trend information by species or subspecies if available. Table adapted from Morrison et al. (2006). COMMON NAME

SUBSPECIES DESIGNATED

DECLINE1

COMMON NAME

Black-bellied Plover

P.s. squatarola

DEC

Wilson's Phalarope

DEC

Snowy Plover

C.a.nivosus

DEC

Red-necked Phalarope

DEC

Mountain Plover

DEC

Western Sandpiper

DEC/U

Lesser Yellowlegs

DEC

Semipalmated Plover

STA/U

Solitary Sandpiper

T.s. solitara and cinnamomea

Black-necked Stilt

DEC

Upland Sandpiper

DEC

Long-billed Curlew

DEC

Marbled Godwit

L.f. fedoa

DEC

Red Knot

C.c. roselarri

DEC

SUBSPECIES DESIGNATED

H.m. mexicanus

Greater Yellowlegs Willet

DECLINE1

STA/U STA/U

T.s. inornatus and semipalmatus

STA/U

Baird's Sandpiper

STA/U

Stilt Sandpiper

STA/U

Long-billed Dowitcher

STA/U

Sanderling

DEC

Semipalmated Sandpiper

DEC

Killdeer

STA

Least Sandpiper

DEC

American Avocet

STA

Pectoral Sandpiper

DEC

Spotted Sandpiper

STA

DEC

Whimbrel

Dunlin

C.a.pacifica

Wilson's Snipe

DEC

Short-billed Dowitcher

1

L.g. caurinus

N.p. rufiventris

U

STA

DEC = decline, STA = stable, U = unknown

The USSCP provides more detailed information on the status of each species through Regional Conservation Scores (Appendix II). These can be used as a tool for partners in prioritizing species and habitat conservation measures by species and season of use at a regional, national, and BCR scale.

5.12

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THREATS & LIMITING FACTORS Water Quantity and Quality

Habitat Loss or Degradation

Degradation of water quality or changes in water quantity are the most pervasive threats to shorebird habitat conservation in the Intermountain West. Water loss can occur in many ways and is almost always exacerbated by the other threats listed in this section. In fact, loss of water is typically the outcome of the threats listed below. It can affect shorebirds directly or indirectly and can occur at the source or thousands of miles away. Historic and contemporary policies pertaining to the protection and use of water in the arid West prioritize agriculture and municipal uses over environmental uses such as wetland management for migratory birds (Downard 2010). Wetland complexes critical to western shorebird populations such as Mono Lake, Great Salt Lake, Lahontan Valley, and Klamath Basin have all been subject to significant declines in water supply due to diversion and withdrawal of water from inflow streams and tributaries, primarily for agricultural purposes (Jehl 1994, Ivey 2001, Downard 2010). Increasing competition for water supplies stemming from population growth in the region is further taxing already limited water resources in the arid Intermountain West.

The USFWS report, Status and Trends of Wetlands in the Conterminous United States 1998– 2004 (Dahl 2006), provides the best overall assessment of the status and trends in wetlands by assessing a subset of randomly selected established wetland plots throughout the U.S. This report identified a decline in freshwater emergent marshes by approximately 142,570 acres throughout the U.S. from 1998–2004. Urban and rural development accounted for an estimated 61% of freshwater wetland loss in the U.S. An additional 8% was lost to drainage or filling of wetlands for silviculture. The wetland loss during this period was offset by a net gain of wetlands that were restored on agricultural lands, primarily through federal conservation programs such as the USDA’s Wetlands Reserve Program (WRP). WRP provides excellent shorebird habitat in some regions (e.g., the Central Valley of California) but its value to shorebirds is influenced by the level of vegetative disturbance conducted annually by private landowners. However, in the absence of vegetative disturbance, WRP wetlands generally trend toward late succession emergent marshes that are not favorable to most shorebirds. This vegetative disturbance usually only occurs in the Intermountain West when the Natural Resources Conservation Service issues Compatible Use Authorizations (CUA) to landowners for haying or grazing. The potential exists to improve WRP wetlands for shorebirds through CUAs, but this has not materialized at large scales to date. Thus, the restoration of wetlands through WRP and other similar programs likely has not offset losses of shorebird habitat in the Intermountain West.

Timing and availability of an adequate quantity of water in the Intermountain West is of primary concern. This issue is further exacerbated by periodic drought cycles. Diversion of water for irrigation or changes in irrigation practices for water conservation can lead to a significant impact on the availability of water during important stages of the shorebird life cycle. This is particularly important during chick rearing since the young must have fresh water for survival. Once that water is no longer available, chicks must move overland to the next water source, exposing them to further threats. Conversely, an increase in water levels also can be detrimental to most shorebirds. This can occur due to increased incidence of flooding events, changes in water delivery, or through conversion to deepwater wetlands or those with very steep slopes that render the habitat unsuitable for shorebirds. Shorebirds such as the Snowy Plover, American Avocet, and Blacknecked Stilt typically nest near the water’s edge, leaving nests susceptible to flooding. In addition, most shorebirds must have shallow water to forage. Water quality is just as important as quantity. Poor water quality is essentially symptomatic of other threats identified in this section. Examples include increased sedimentation from runoff due to loss of wetland buffer habitat, concentrations of contaminants such as selenium from agricultural runoff, and increased concentration of salt in water beyond the physiological limit of chicks to process.

5.13

Nationally, the creation of freshwater ponds has contributed substantially to the net gain of wetlands. However, the majority of these ponds are not an equivalent replacement for wetland loss for shorebirds. In fact, artificial ponds are seldom used by shorebirds as they are typically constructed with steep banks that limit access for foraging. Dahl (2006) noted an increase in deepwater lake and reservoir acreage; but did not provide an assessment of ephemeral wetlands, an important wetland habitat for shorebirds in the Intermountain West.

Agriculture One of the primary reasons for wetland and native grassland loss in the Intermountain West is due to conversion to croplands. In addition, many agricultural practices such as water diversion, changes in irrigation practices, herbicide applications, harvest during the nesting season, and maintenance of extensive monocultures can have negative impacts on shorebird habitat. For instance, grassland loss could cause site abandonment by adults and increased nest and chick

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THREATS & LIMITING FACTORS loss due to lack of cover. However, agricultural uses can provide protection from urbanization and thus more realistic opportunities for future habitat restoration. In addition, they can provide important feeding and staging areas for some species such as Wilson’s Phalarope. In the Harney Basin, Oregon, the private hay fields of the Silvies River Floodplain support thousands of breeding shorebirds (Paullin et al. 1977). Fledging shorebirds in this area were especially vulnerable to mortality from hay cutting. As an example, one mower operator estimated that he killed 400–600 birds between July 1 and 13. The most common bird killed was Wilson’s Phalarope; other mortalities included Long-billed Curlew, Sora, Common Snipe, and blackbirds. Unlike ducks, the shorebirds and especially the Wilson’s Phalarope, tend to remain in hay meadows to feed after hatching. Consequently, even the earlier nesting species are vulnerable to mowing. The rate of mortality declined throughout the haying season as more birds fledged, and most critical period for mowing mortality in 1976 was the first two weeks in July. Hay cutting begins as early as mid-June on the Silvies River River Floodplain and other native hay meadows in eastern Oregon, which likely causes even higher rates of shorebird mortality. A related problem affecting shorebird survival in hayfields is early de-watering. Water is drained from hayfields about three weeks before mowing commences. This action reduces food supplies and tends to concentrate young birds near remaining water, thus increasing their vulnerability to predators (Oring et al. 2000). Flood irrigated hay meadows provide benefits to many other wetland dependent birds such as migrating and breeding ducks and waterbirds. Given the diversity of annual cycle requirements, achieving multiple species habitat objectives on the same acres is predictably challenging, especially on private lands with other land management objectives. Thus, a landscape level approach to evaluate the habitat needs of priority species in reaction to the conservation estate and management practices is required.

Rural Urbanization The Intermountain West has experienced unprecedented human population growth over the past two decades. While high-density metropolitan areas (e.g., Salt Lake City, Utah) have experienced high population growth, traditionally rural intermountain valleys throughout the Intermountain West have witnessed substantial population growth as well. These intermountain valleys were historically populated by humans at low density and typically centered around agricultural production, namely ranching. The rapid increase in rural urbanization has drastically altered the landscape composition and has left many intermountain valleys highly fragmented from only two decades ago. Urban development typically results in 5.14

an irreversible loss of wetlands (Dahl 2006). The indirect effects of development on shorebirds can be just as harmful. With increased housing in rural or urban areas comes increased predation from pets and feral cats. Rural urbanization reduces surface and groundwater levels due to changes in water rights and uses and alters hydrologic conditions that may change the location or rate of runoff as well as compromised water quality.

Invasive Species Invasive species, particularly plant species, can have a drastic affect on habitat quality. With poor nesting cover, breeding birds are more susceptible to disturbance or predation. In some areas, invasive species such as phragmites (Phragmites australis) have colonized open areas historically used for nesting. Grasslands at lower elevations have been heavily impacted by invasive exotic species such as cheatgrass (Bromus tectorum). Wetlands throughout the west are becoming choked by phragmites, tamarisk (Tamarix spp.), and purple loosestrife (Lythrum salicaria), and shoreline habitats traditionally used for foraging and nesting are therefore no longer available. Upland habitats are also at risk. Dikes and levees around impoundments or reservoirs that provide nesting habitat can become chocked with invasive weeds (e.g., knapweed [Centaurea spp.] or thistle [Cirsium arvenre) and they become unsuitable for nesting shorebirds. In some areas, over grazing and suppression of natural fire regimes followed by invasion by cheatgrass has led to the loss of grassland, particularly in southeastern Oregon and the Columbia Plateau. Poorly managed livestock grazing in wet meadows can result in trampled nests, compaction of the soil, and reduced water quality. Invasive, non-native mammals can directly and indirectly effect shorebirds and their habitat. Non-native herbivores can destroy habitat through forage pressure or become a year-round food source for predators. Predators, such as red foxes, raccoons, or rats, can prey on eggs, chicks, and adults. Raccoons and foxes were unknown in the Salt Lake Valley of Utah prior to the 1970s but occur at high densities now. Changes in predator communities have likely impacted demographic performance of shorebirds at this continentally significant area. Invasive species eradication involves a long-term commitment and can be expensive. Without a coordinated effort throughout the affected area, eradication on one property may not be effective over the long term if an adjacent property still hosts invasive species. To exacerbate the issue, little is known regarding how to control certain invasive species (e.g., cheatgrass) or the effects of removal on focal breeding species such as the Long-billed Curlew, which shows a preference for cheatgrass habitats in southeastern Washington (Pampush and Anthony 1993). Furthermore, control of invasive species

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THREATS & LIMITING FACTORS often supersedes other habitat or species conservation measures for management time or funding.

Contaminants and Disease Outbreaks Concentrations of contaminants in wetlands are of conservation concern in the Intermountain West. Prevalent contaminants include selenium, mercury, DDT, and DDE. DDT and its metabolite DDE have been proven in numerous studies to reduce hatching success of all birds due to egg shell thinning. Selenium is known to reduce hatching success and increase chick mortality. Similarly, mercury contamination reduces reproductive success in shorebirds. Salinities in large Great Basin hypersaline lakes such as the Great Salt Lake, Lake Abert, and Mono Lake and the saline sinks of Lahontan Valley are of increasing concern for shorebirds. Each of these areas face human-induced water level manipulations which alter salinity concentrations and can influence contaminant cycling (Naftz et al. 2008). Furthermore, altered hydrology can cause reduced or increased salinities beyond the tolerance of shorebird chicks and prey (e.g., brine flies and brine shrimp; Oring et al. 2000). Large-scale die-offs of aquatic birds due to disease outbreaks have been reported in wetland complexes, although shorebirds compose a small percentage of birds affected relative to other species. Causes of die-offs range from botulism to cholera.

Other Anthropogenic Factors Altered fire and flood regimes have also lead to the loss of grasslands by altering plant community dynamics and succession. By controlling or severely limiting the natural fire regime of grassland habitats, early seralstage grasslands have been replaced by woodlands and shrub-dominated habitats. These habitats have lower suitability for shorebirds and likely impact demographic performance. Transition back to functional grassland habitats often requires expensive and intensive restoration treatments. Additionally, altered hydrologic patterns from dams and other water control structures can significantly impact wetland plant and invertebrate communities through alteration of nutrient transport within a system.

Climate Change All of the above threats may be exacerbated by climate change. Many of the direct and indirect effects of climate change on shorebirds and their habitats are unknown however, which hinders proactive conservation measures. Scientists are predicting that species with low genetic

5.15

diversity, those that breed in the arctic and boreal forest zone, as well as birds that breed in arid environments will be more heavily affected by climate change (NABCI 2010, Climaterisk.net; Meltofte et al. 2007). Migrants are also at risk due to the limited number of secure water sources and the limited extent of wetlands in the Intermountain West. These predictions place shorebirds of the Intermountain West at greater risk than most species, because the majority of the species passing through the Intermountain West breed in the Arctic. In addition, Arctic breeding shorebirds are known for low genetic diversity (Meltofte et al. 2007). Climate change can have a profound influence on habitat suitability as well. Climate change may result in an overall increase or decrease in precipitation, changes in the intensity and frequency of precipitation events, or shifts in the seasonal patterns of precipitation that will affect the available supply of water. For instance, decreased snow pack results in less water runoff into intermountain basins during the drier summer months. Conversely, increased runoff or flooding events could increase erosion and/or decrease available habitat. The phenology of snow pack runoff has also been shifting in the Intermountain West. Changes in the timing or runoff will likely influence wetland plant and invertebrate community dynamics which shorebirds have evolved to exploit. Combined with other issues affecting shorebird habitat, climate change could prove devastating for shorebirds that rely most on the ephemeral habitats of the Intermountain West. If wetland quality, abundance, or distribution is compromised in the Intermountain West in such a way that migratory connectivity is significantly impaired then survival and recruitment rates for these populations will also be affected. Demand for water to meet agricultural or urban needs will also increase with increasing temperatures. With decreasing water supplies and increasing temperatures, the risk of harmful algal blooms, concentration of contaminants, and frequency of diseases increases. Decreased water quality will impact invertebrate food sources thereby forcing migrant shorebirds to either remain at each stopover site longer to meet physiological needs or continue migration under less than ideal physical condition. Breeding shorebirds may be forced to adapt to habitat changes or decreases in foraging resources by shifting their breeding range. This in turn can lead to a mismatch in timing of availability of food resources or changes in food resources. In addition, shifts in species range or changes in habitat may facilitate spread of invasive species that degrade shorebird habitats.

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POPULATION ESTIMATES & OBJECTIVES Population Estimates Primarily due to a lack of information, the IWRSCP stopped short of developing population estimates for shorebirds in the Intermountain West. Therefore, the SST developed population estimates and objectives based on the best available data for breeding and passage shorebirds (Table 5). Estimates were developed from a top-down approach using the most current continental and flyway population estimates provided in Morrison et al. (2006). These estimates were then adjusted through a bottom-up process. For passage shorebirds, population estimates were derived from a summation of data from the Pacific Flyway Project (Shuford et al., 2002) for most sites, augmented by site-specific data (Table 5). These estimates reflect the sum of peak counts of passage shorebirds either from spring or fall migration at key sites. For breeding shorebirds, population estimates were derived from Breeding Bird Survey (BBS) data and species-specific surveys. The top-down and bottom-up estimates were compared and adjustments were made for particular species. For instance, the passage Long-/Short-billed Dowitcher estimate was reduced because site specific data were collected during a very high period in the water cycle and abundance was at or near peak levels. Thus the estimate did not represent abundance levels during an average water year; therefore, the dowitcher population estimate was subsequently reduced.

Assumptions and Limitations of Data Several assumptions were made during the development of population estimates, primarily that the sums for peak counts of each species accurately reflect the passage shorebird population in the Intermountain West. These sums represent non-standardized data collected during different years or using different methods. Also, many of the estimates presented were derived based on data collected 20 years ago. In addition, this process does not adequately address dispersed species such as the Greater andLesser Yellowlegs or Spotted Sandpiper. Data collected for the BBS were used to calculate breeding shorebird population estimates across the Intermountain West. However, the BBS does not adequately cover wetland breeding habitats and many shorebird species are under sampled.

5.16

Due to the limitations of the data, population estimates should be interpreted as an indicator of the population. For this reason, one of the highest monitoring priorities is to collect standardized distribution and abundance data for passage shorebirds at all sites. Range-wide breeding shorebird surveys are needed to provide both Intermountain West-specific estimates and range-wide estimates from which to assess the importance of the Intermountain West to each species. Finally, a properly designed study is needed to sample dispersed migrants.

Regional Population Objectives The SST set 30-year population objectives for the Intermountain West from the top-down using numeric objectives set in the USSCP. Objectives were set based on the most current population estimates and data on status (Morrison et al. 2006). Options considered were: maintain current levels, increase by 25%, or increase by 50%, or use increases reported in USSCP. These options are generally consistent with the approach used by Partners in Flight for establishing trend-based objectives for landbirds. Limiting factors, the importance of the IWJV to the species, and ability to manage the species habitat were considered when assessing options for setting objectives. The team reviewed each species objective during the breeding and nonbreeding season and agreed on a numeric objective for each season. Maintaining current population levels will likely require more conservation action than was required during the formation of the IWJV given the loss of grasslands and wetlands in the region. In addition, assessing whether objectives have been met for secretive or cryptic species such as the Wilsonâ&#x20AC;&#x2122;s Snipe will be difficult due to issues of detectability. The assumptions and limitations listed above apply equally to the objectives. Site and in some cases population monitoring is key to evaluate progress toward objectives for all species and habitats. For more information, see the Monitoring and Research section of this chapter.

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POPULATION ESTIMATES & OBJECTIVES Table 5 P  opulation estimates and objectives for passage shorebirds by BCR in the Intermountain West JV area. JV TOTAL (SUM OF SITE COUNTS)

IWJV ADJUSTED ESTIMATE

IWJV OBJECTIVE

BCR 9 ESTIMATE

BCR 9 OBJECTIVE

 lack-bellied B Plover

13,567

15,000

27,270

13,556

27,250

0

0

8

20

3

10

 emipalmated S Plover

2,300

3,000

3,000

2,178

2,840

0

0

41

50

81

110

Killdeer

14,490

50,000

50,000

13,749

47,440

63

220

606

2,090

72

250

 lack-necked B Stilt

86,902

120,000

120,000

86,513

119,460

0

0

344

480

45

60

438,960

420,000

420,000

430,094

411,520

71

70

7,788

7,450

1,007

960

 potted S Sandpiper

3,688

10,000

10,000

3,589

9,730

0

0

89

240

10

30

 olitary S Sandpiper

144

3,000

3,000

127

2,650

0

0

4

80

13

270

 reater G Yellowlegs

2,765

12,000

12,000

2,368

10,280

0

0

375

1,630

22

100

Willet

8,184

50,000

50,000

8,111

49,550

18

110

49

300

6

40

Lesser Yellowlegs

5,612

15,000

15,000

4,285

11,450

0

0

1,317

3,520

10

30

21

1,000

1,000

15

710

0

0

0

0

6

290

46,298

130,000

162,500

45,823

160,830

0

0

463

1,630

12

40

26

1,000

1,000

25

960

0

0

1

40

11,641

15,000

15,000

11,540

14,870

0

0

100

130

1

0

223

1,000

1,000

49

220

0

0

171

770

3

10

366,823

500,000

500,000

360,491

491,370

0

0

1,312

1,790

5,020

6,840

Least Sandpiper

88,028

100,000

100,000

85,310

96,910

0

0

222

250

2,496

2,840

 aird's B Sandpiper

10,953

35,000

35,000

1,986

6,350

0

0

8,967

28,650

0

 ectoral P Sandpiper

425

1,000

1,000

382

900

0

0

43

100

0

24,713

25,000

27,500

24,701

27,490

0

0

2

0

PASSAGE SHOREBIRDS

American Avocet

Whimbrel Marbled Godwit Red Knot Sanderling  emipalmated S Sandpiper  estern W Sandpiper

Dunlin Stilt Sandpiper

BCR 10 ESTIMATE

BCR 10 OBJECTIVE

BCR 16 ESTIMATE

BCR 16 OBJECTIVE

BCR 33 ESTIMATE

BCR 33 OBJECTIVE

0

10

10

62

5,000

5,000

27

2,180

0

0

35

2,820

Dowitcher

232,864

250,000

256,000

231,214

254,190

12

10

1,551

1,710

87

100

0

 ilson's W Phalarope

621,666

750,000

850,000

589,434

805,930

1,200

1,640

30,787

42,090

245

330

 ed-necked R Phalarope

339,639

350,000

350,000

339,301

349,650

0

0

207

210

131

130

Note: Due to lack of data, no estimates or objectives are provided for passage shorebirds in BCR 34 and 35 within the IWJV. In addition, portions of BCRs 34 and 35 in the IWJV provide very little habitat for passage shorebirds.

5.17

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POPULATION ESTIMATES & OBJECTIVES Table 6 P  opulation estimates and objectives for breeding shorebirds within BCRs 9, 10, 16, 33, 34, and 35 in the Intermountain West Joint Venture. JV ADJUSTED ESTIMATE

BREEDING SHOREBIRDS

Snowy Plover Killdeer

9,400

JV OBJECTIVE

9,400

150,000 300,000

BCR 9 ESTIMATE

8,800

BCR 9 OBJECTIVE

BCR 10 OBJECTIVE

BCR 16 ESTIMATE

BCR 16 OBJECTIVE

BCR 33 ESTIMATE

BCR 33 OBJECTIVE

BCR 34 ESTIMATE

BCR 34 OBJECTIVE

BCR 35 ESTIMATE

BCR 35 OBJECTIVE

8,800

0

0

150

150

450

450

0

0

0

0

62,550 125,100

30,000

60,000

15,450

30,900

16,650

33,300

6,300

12,600

15,750

31,500

3,819

5,700

2,900

4,300

0

0

0

0

0

0

2,400

2,400

2,760

2,760

12,720

12,720

0

0

5,520

5,520

7,500

7,500

5,500

5,500

18,250

18,250

0

0

8,500

8,500

7,950

7,950

2,280

2,280

0

0

0

0

0

0

Mountain 6,700 10,000 0 0 Plover Black-necked 120,000 120,000 96,120 96,120 Stilt American 250,000 250,000 206,000 206,000 Avocet Spotted 15,000 15,000 2,925 2,930 Sandpiper Willet

BCR 10 ESTIMATE

20,000

20,000

14,500

14,500

3,800

3,800

0

0

0

0

0

0

0

0

300

400

0

0

0

0

0

0

0

0

0

0

0

0

70,000

99,700

47,810

68,100

19,600

27,920

2,940

4,190

0

0

0

0

0

0

1,000

1,500

0

0

1,000

1,500

0

0

0

0

0

0

0

0

Wilson’s Snipe 20,000

30,000

5,760

8,640

8,400

12,600

3,240

4,860

0

0

0

0

0

0

195,000 292,500 104,910 157,370

35,100

52,650

36,660

54,990

0

0

0

0

0

0

Upland Sandpiper Long-billed Curlew Marbled Godwit

Wilson’s Phalarope

P h o t o b y J o s h Ve s t

5.18

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KEY SITES FOR SHOREBIRD CONSERVATION Conservation strategies based on key sites are intended to provide a more detailed approach to implementing objectives of the IWJV Implementation Plan. Since the key-site strategies are developed by all interested conservation partners in the area, they provide a tie in with land managers and site-specific source of information for the development of project proposals for IWJV funds or partners programs. Due to the smaller scale of Key-Site Conservation Strategies, they can focus on site-specific conservation needs, challenges, and priorities. The SST identified both primary and secondary key sites for conservation action. The objective of this approach is for the JV partnership to ultimately develop a key-site strategy for all primary key sites, effectively capturing a

majority of the migratory shorebird habitat conservation needs throughout the IWJV and a significant portion of shorebird breeding habitats of the Intermountain West. Primary key sites represent important shorebird sites identified by the IWRSCP and WHSRN within the IWJV boundary as well as any sites that support greater than 5,000 shorebirds during peak migration count periods, or greater than 1% of a biogeographic population of a shorebird species in any one season. Each of these sites is part of a BHCA identified in the 2005 IWJV Implementation Plan. The 1% criterion is consistent with that of WHSRN and several other national and international bird conservation groups as a threshold to identify important sites for shorebirds worldwide.

Table 7 S tatus of Primary Key Sites according to Western Hemispheric Shorebird Reserve Network criteria. PRIMARY KEY SITE

PEAK MIGRATION COUNT

HEMISPHERIC1

INTERNATIONAL2

REGIONAL3

UT - Great Salt Lake (a)4

1,484,350

Peak Count 67% American Avocet 38% Black-necked Stilt 33% Wilson’s Phalarope

26% Marbled Godwit 24% Blackbellied Plover

1% Willet

UT - Fish Springs NWR (b,g)

9,588

UT - Ouray NWR (h)5

6,067

OR - Harney Basin (b,c)

84,659

Peak Count 4% Dow sp. 2% American Avocet & Spotted Sandpiper 1% Wilson’s Phalarope & Black-necked Stilt

OR - Summer Lake (b)

34,238

Peak Count

OR - Lake Abert (b)

83,031

Peak Count

OR - Warner Basin (b)5

11,703

CA/OR - Klamath Basin (b,d)

64,318

Peak Count

CA/OR - Goose Lake (b)

37,224

Peak Count

CA/NV - Honey Lake (b)

21,609

Peak Count

CA - Alkali Lakes (b)

19,294

Peak Count

CA - Owens Lake (b)5

9,280

CA - Mono Lake (b)

102,676

NV - Lahontan Valley (b,e)

214,306

NV - Humboldt WMA (b)

25,628

ID - Am. Falls Res. (b)5

7,299

ID - Lake Lowell (b)5

12,571

CO - San Luis Valley (f)

46,016

Peak Count 38% Long-billed Dowitcher

3% Wilson’s Phalarope 2% American Avocet

Peak Count Peak Count

Peak Count

Hemispheric - At least 500,000 shorebirds annually or >30% of a biogeographic population. International - At least 100,000 shorebirds annually or >10% of a biogeographic population. Regional - At least 20,000 shorebirds annually or >1% of a biogeographic population. 4 Sources: (a) Paul and Manning 2002; (b) Shuford et.al. 2002; (c) Ivey et al. unpubl.; (d) Shuford et al. 2006; (e) Neel and Henry 1997; (f) BLM unpubl. data; (g) Fish Springs unpubl. data; (h) NWR unpubl. data - highest counts over 7 years of data. 5 Intermountain West Joint Venture Key Site criteria: > 5,000 individual shorebirds during peak migration. 1 2 3

5.19

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KEY SITES FOR SHOREBIRD CONSERVATION

15 16

17

18

14 11 12 13 10 8 9

Due to concern that the focus on key sites does not adequately address dispersed migrants or dispersed breeding shorebirds, the SST also identified secondary sites for conservation action. They include sites that support less than 5,000 migrants during peak counts over one migration season (Shuford et.al. 2002). These sites represent a lower priority than the 18 key sites for shorebird conservation planning and habitat conservation delivery.

1 2 3

7

4

5 6

Table 8 S  econdary sites for shorebird conservation within the Intermountain West identified by the Shorebird Science Team. STATE

SITE

WA

Othello Sewage Ponds Walla Walla River Delta

Figure 2 P  rimary Shorebird Key Sites in the Intermountain West Joint Venture. 1 = American Falls Reservoir, 2 = Great Salt Lake, 3 = Fish Springs NWR, 4 = Ouray NWR, 5 = San Luis Valley, 6 = Owens Lake, 7 = Mono Lake, 8 = Humboldt WMA, 9 = Lahontan Valley, 10 = Honey Lake, 11 = Klamath Basin, 12 = Goose Lake, 13 = Alkali Lakes, 14 = Warner Basin, 15 = Summer Lake, 16 = Lake Abert, 17 = Harney Basin, 18 = Lake Lowell.

UT

Utah Lake

CA

Butte Valley Modoc NWR Lyneta Ranch Bridgeport Reservoir Crowley Lake

NV

Long Valley Continental Lake Sleeper Mine Pyramid Lake Ruby Valley Key Pitman WMA Henderson Sewage Ponds

WY

Mortenson Lake NWR Hutton Lake NWR

CO

Arapaho

P h o t o b y J o s h Ve s t

5.20

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KEY SITES FOR SHOREBIRD CONSERVATION The Great Salt Lake Key Site Conservation Strategy The Great Salt Lake (GSL) was selected as a site for development of a key site conservation strategy (GSL Strategy) due to its importance to shorebirds (Table 7), the size and complexity of habitats, and the existence of an active bird conservation community. The intent of the document was to provide a strategic approach to shorebird conservation that was developed by the primary stake holders active in shorebird conservation on the GSL and linked to explicit continental and regional population objectives. One of the primary tools developed in this effort was an energetic model for use in linking population objectives with habitat objectives. As a result, much of the GSL Strategy addresses important components of the models. This bioenergetic approach is focused on the nonbreeding component of the annual life cycle. A primary assumption in this strategy is that food is a primary limiting factor during post-breeding and migration in meeting annual life cycle requirements for shorebirds. Components of the model are similar to those identified for the Blanca Wetlands key site conservation strategy (see below), however a higher degree of complexity has been incorporated into the GSL model inputs. The GSL Strategy goes beyond identifying habitat needs, it also identifies human growth trends and threats to shorebirds and their habitats; provides detailed conservation actions to abate and mitigate threats; and identifies potential conservation partnerships and programs that may facilitate these actions. The entire GSL system occupies roughly 3,011 square miles, consisting of the following regions: Bear River Bay, Farmington Bay, the Gilbert Bay (south arm) and Gunnison Bay (north arm), and adjacent wetland complexes. GSL water levels are extremely dynamic and change in response to long-term precipitation cycles, seasonal changes in evaporation and inflow, and daily influences from wind-driven seiches. As a result, the strategy incorporates the effects of seasonal or annual variation in habitat availability in the form of area estimates for low and average lake levels. This is particularly relevant when considering the amount of suitable habitat along the transient shoreline that can migrate seasonally back and forth for hundreds of yards. During dry cycles, there can be vast reaches of dry mud flat (less productive shorebird foraging habitats, but some plover nesting habitat) several miles between the shoreline where birds actively feed and the nearest other wetland type. Conversely, shallow wetland habitat may be severely limiting during periods of high precipitation as experienced in the mid-to-late 1980s. As a result a 5.21

shoreline buffering technique was employed to more accurately account for functional shoreline habitat and the macro-invertebrate population it supports. The GSL shorebird team recognized that not all acres within and between habitat types have equal foraging value to shorebirds. As a result, they adopted quality designations recently identified by Ducks Unlimited within the GSL ecosystem. These habitat-quality indicators provide condition classification habitat type, location and acreage. These acreages will be used to model GSL capacity for migratory shorebirds. In addition, macroinvertebrate populations can be influenced by changing salinities, which in turn are influenced by water volume. Invertebrate biomass densities were determined from three previous studies conducted in wetlands surrounding the GSL (Huener 1984, Cox and Kadlec 1995, Johnson 2007). These studies spanned an interval of 23 years and provide invertebrate information prior to and immediately after the 1980s GSL flooding event. Shorebird population objectives were stepped down from continental and regional objectives identified in this chapter. Population objectives were fitted to annual migration phenology based on data derived from the GSL Waterbird Survey conducted from 1997â&#x20AC;&#x201C;2001. Over 54.5 million total shorebird use-days were calculated during fall migration and 16.6 million use-days during spring based on these population objectives. These use-day estimates were applied to species specific energetic demands to identify foraging habitat objectives for shorebirds. Bioenergetic assessments of fall migrating shorebirds in the Great Salt Lake indicate at least 277,000 acres of suitable shorebird-foraging wetlands (i.e., shallow water and sparse vegetation) are required in the GSL to meet population energy demands during fall migration and approximately 87,000 acres during spring migration. Current understanding of wetland productivity and availability to shorebirds limits the ability to assess whether the current conservation estate is able to meet these population demands within the GSL system. Improved understanding of wetland productivity and relationships to hydrologic dynamics will greatly improve the ability to inform and develop explicit conservation targets and strategies for shorebirds and other wetland dependent birds in the GSL system. The true â&#x20AC;&#x2DC;conservationâ&#x20AC;&#x2122; component of the Strategy provides information on conservation partners and landowner priorities, trends in population growth and subsequent development, as well as site-specific threats. Site partners conducted a detailed assessment of the conservation estate considering land ownership, management status, and vulnerability (e.g., to mineral

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BREEDING SHOREBIRD FOCAL SPECIES extraction or change in ownership status). The Great Salt Lake Key-Site Strategy provides a comprehensive assessment of shorebird habitat in the Great Salt Lake and a conservation strategy designed with site- and species-specific data collected at GSL and management recommendations identified by active conservation partners in the ecosystem.

habitats. Because direct information was lacking on shorebird diets at Blanca WHA, the most plausible values reported in the literature from saline ponds in the Playa Lakes region were used. Because of the uncertainty involved with these surrogate values, habitat requirements of passage shorebirds under four forage density values were estimated.

Blanca Wetlands Shorebird Habitat Strategy

Analysis of shorebird counts suggests that Blanca WHA supports more passage shorebirds than previously recognized, particularly during post-breeding migration. The most abundant passage shorebird species included Wilsonâ&#x20AC;&#x2122;s Phalarope, American Avocet, and Bairdâ&#x20AC;&#x2122;s Sandpiper. Our results indicate that playas on Blanca WHA did not meet the bioenergetic needs of the observed population of passage shorebirds (47,108) and would not have meet the needs of a site-specific population objective of 49,226 shorebirds. Our results indicate that under all but the highest forage density, deficits in meeting the energetic requirements occurred during peak post-breeding migration in early to mid-August.

The Blanca Wildlife Habitat Area is a complex of wetlands managed by the Bureau of Land Management (BLM) in the San Luis Valley of south-central Colorado. The San Luis Valley has been identified as a primary Key Site for shorebird conservation in the Intermountain West (Table 7.) The IWJVâ&#x20AC;&#x2122;s SST elected to use a bioenergetic approach to develop shorebird habitat objectives that are explicitly linked to national and regional shorebird population objectives. Blanca WHA is an important stopover site to passage shorebirds in the eastern IWJV. Blanca WHA was selected for testing the viability of bioenergetics modeling as an assumption-based decision support tool for local land managers, while contributing to the knowledge base of shorebird habitat use and supply in the IWJV. This effort was collaborative and included members of the SST, local BLM wetland managers, Colorado Division of Wildlife biologists, and BLM biologists. Shorebird survey and habitat data collected by the BLM from 2002 to 2007 were used to generate inputs to a bioenergetic model: population objectives, daily food requirement, habitat availability, and energy supplied by playas. Basic carrying capacity equations were used to evaluate bioenergetic demand and supply. Dietary differences during pre- and post-breeding periods were assessed and a range of food items were incorporated in the estimates of energy available in playa foraging

5.22

Shorebird habitat management actions on Blanca WHA should focus on increasing the quantity or quality, relative to the density of shorebird prey items, of playas in late July through August. Further monitoring is also needed to test assumptions of the energetics model and to address data limitations. We provide monitoring and research recommendations that would reduce current uncertainties, particularly around the forage density value. Management recommendations are also provided to reduce the predicted deficits in energy supplies. A next step in the shorebird bioenergetics approach would be to consider all wetland types within the Blanca WHA boundary and possibly within the entire San Luis Valley.

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BREEDING SHOREBIRD FOCAL SPECIES Habitat objectives for breeding shorebirds in the Intermountain West have not been developed for this implementation plan update. However, the Intermountain West contains critical breeding habitat for many shorebird species. The IWJV partnership should therefore strive to develop habitat objectives for important shorebird species as identified through the biological framework discussed in chapter 3 of the implementation plan update. However, the SST has identified a suite of priority breeding shorebird species from which focal species can be selected to focus more detailed biological planning and develop appropriate conservation strategies. Development of meaningful conservation strategies around focal breeding shorebirds will be dependent on the availability of information related to both population demographics and relationships to landscape or habitat metrics. Priority species were selected because relatively little is known about breeding shorebird distribution, abundance, or limiting demographic parameters within the Intermountain West. Priority species also represent shorebirds of the highest conservation priority by partners (state, NAWCA, and BCC/BMC) in the Intermountain West. However, the list of priority species identified here may not represent true umbrella or indicator species (Lindenmayer et al. 2002). Priority species were selected based on a variety of factors including: • high conservation scores listed in the IWRSCP (Highly Imperiled or Species of High Concern) • high Area of Importance scores (the area is critical or important to support hemispheric or regional populations) which signifies a high stewardship value, or • high degree to fidelity to important habitat types in the IWRSCP Data used to identify priority breeding shorebirds represent peak counts by species during one migration season. As a result, data provided in the table above represent a minimum abundance (one season). A more accurate representation of the magnitude of use at any site should be presented by counts collected throughout an annual cycle. Further, many of the data presented above were collected in the early 1990’s and should be updated.

5.23

Focal Species Profiles Snowy Plover: This species was selected as a focal breeding species because the Intermountain West is considered ‘critical to supporting hemispheric populations’ of Snowy Plover (AI = 5, USSCP). This Photo by Utah Division species also was selected because relatively of Wildlife Resources current breeding densities per site are available from the results of a comprehensive, range-wide survey of breeding plovers conducted in 2007. Large saline lakes, ephemeral wetlands/playas, and man-made impoundments with a relatively consistent source of water and little to no vegetative cover are important habitat components. Changes in water management practices, drought or flooding, and vegetative encroachment may limit habitat availability. Wilson’s Phalarope: Wilson’s Phalarope was also selected as a focal breeding shorebird species because the Intermountain West is ‘critical to supporting Hemispheric populations’ (AI = Photo by Utah Division 5, USSCP). This is a species of marshes of Wildlife Resources and lake/marsh complexes and irrigated agricultural fields. They favor tall, dense vegetation within 100 meters of wetlands. Limiting factors include loss of habitat and lack of sufficient water in breeding and foraging habitats (Colwell and Jehl 1994). Wilson’s Phalaropes can also be affected by changes in irrigation practices which limit water runoff and eliminate standing water in flooded fields (Lesterhuis and Clay 2009). Long-billed Curlew: Long-billed Curlew also receives the highest conservation ranking within the IWJV (i.e. highly imperiled and critical to supporting hemispheric populations). Long-billed Photo by Utah Division Curlews prefer open grasslands (short to of Wildlife Resources mixed grass and open or recently grazed pastures) with maximum heights less than 30 cm (Fellows and Jones 2009) Researchers speculate that proximity to wetland habitats within one mile of nest sites is preferred, however this has not been definitively proven. Long-billed Curlew was selected by the Partners in Flight Western Working Group as a species to develop habitat objectives for through the HABPOPs model in upland habitats (refer to Landbird Chapter). Thus, habitat and population assessments for Long-billed Curlew are addressed in the Landbird Chapter.

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BREEDING SHOREBIRD FOCAL SPECIES Mountain Plover: Mountain Plovers have a limited distribution within the IWJV in portions of Colorado, New Mexico, Wyoming, and Utah; the Intermountain West is considered critical to supporting Photo by USFWS hemispheric populations by supporting several important breeding areas for this species. The highest density of breeding Mountain Plovers occurs in South Park, Colorado (Wunder et al. 2003). The Mountain Plover is associated with short-grass and shrub-steppe landscapes throughout its breeding range, prefering sites with very sparse, short vegetative cover (e.g., prairie dog colonies, heavily grazed pasture, or recently burned or tilled fields). Habitat loss and degradation appear to limit population growth on the breeding grounds (Knopf 1996, USFWS 2003). The primary activities that influence degradation or loss include conversion of native grasslands for agriculture, and negative farming and range management practices (Knopf 1996, USFWS 2003). Upland Sandpiper: While the Upland Sandpiper is not considered of conservation concern throughout the Intermountain West, there is a small isolated population in eastern WA and OR that may be genetically Photo by USFWS distinct. Research is needed to determine the status of this small, isolated population. For this reason, this species has been designated as a focal breeding species. Upland Sandpipers are considered grassland obligate species and are restricted to large (>100ha), open tracts of short grassland habitat. Preferred habitats include short-grass prairies, dry meadows, pastures, and hayfields with a variety of vegetation heights and densities (Vickery et al. 2010). Limiting factors include loss of grassland habitats for row crop agriculture.

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American Avocet: The American Avocet was selected because it is relatively common throughout the Intermountain West with approximately half of the global population breeding in the region. They Photo by USFWS commonly nest on dikes, islands, or high spots near large saline lakes, man-made impoundments, ephemeral wetlands and playas, or marshes and lake/marsh complexes. Threats include loss or degradation of breeding habitats and water quality and selenium poisoning. This species responds well to nesting habitat management, especially construction of nesting islands within areas of shallow water. Black-necked Stilt: This species was also selected because Black-necked Stilts are relatively common throughout the Intermountain West. They can be found in similar habitats as American Avocets, Photo by USFWS although stilts prefer more emergent vegetation than avocets. Black-necked Stilts are considered an important indicator species of contaminants in irrigation drain water due to their sensitivity to selenium (Robinson et al. 1999). Other threats include loss of habitat and degradation of water quality. This species responds well to nesting habitat management especially construction of nesting islands within areas of shallow water.

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LITERATURE CITED Brown, S., C. Hickey, B. Harrington & R. Gill, eds. 2001. United States Shorebird Conservation Plan, Second edition. Manomet Center for Conservation Sciences, Manomet, MA. Colwell,, M.A. and J.R. Jehl, Jr. 1994. Wilson’s Phalarope (Phalaropus tricolor) In The Birds of North America, No. 83 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists’ Union, Washington, D.C. Dahl, T.E. 2006. Status and Trends of Wetlands in the Conterminous United States 1998 to 2004. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C. 112 pp. Downard, R. 2010. Keeping wetlands wet: The hydrology of wetlands in the Bear River Basin. 2010. All Graduate Thesis and Dissertations. Paper 829. Utah State University. Graduate Studies, School of DigitalCommons@USU. Online: http://digitalcommons. usu.etd/829 Fellows, S.D., and S.L. Jones. 2009. Status assessment and conservation action plan for the Long-billed Curlew (Numenius americanus). U.S. Department of the Interior; Fish and Wildlife Service, Biological Technical Publication, FWS/BTP – R6012-2009, Washington, D.C. Helmers, D.L. 1992. Shorebird Management Manual. Western Hemisphere Shorebird Reserve Network, Manomet, MA. 58 pp. Intermountain West Joint Venture. 2005. Coordinated Bird Conservation Plan, Ver. 1.1. Online: <http://iwjv.org>. Ivey, G. L. 2001. Joint Venture Implementation Plans for Habitat Conservation Areas in Eastern Oregon: Klamath Basin. Oregon Wetlands Joint Venture, Portland, Oregon. Online: www.ohjv.org/pdfs/klamath_basin %20.pdf. Jehl, J. R., Jr. 1994. Changes in saline and alkaline lake avifaunas in western North America in the past 150 years. Studies in Avian Biology 15:258–272. Knopf, F. L. 1996. Mountain Plover (Charadrius montanus), in The Birds of North America (A. Poole and F. Gill, eds.), no. 211. Acad. Nat. Sci., Philadelphia. Lesterhuis, A. J., and R.P. Clay. 2009. Conservation Plan for Wilson’s Phalarope (Phalaropus tricolor). Version 1.0. Manomet Center for Conservation Sciences, Manomet, Massachusetts.

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Lindenmayer, D.B., A.D. Manning, P.L. Smith, H.P. Possingham, J. Fischer, I. Oliver, and M.A. McCarthy. 2002. The Focal-Species Approach and Landscape Restoration: a Critique. Conservation Biology 16: 338-345. Meltofte, Hans, T. Piersma, H. Boyd, B. McCaffery, B. Ganter, V.V. Golovnyuk, K. Graham, C.L. Gratto-Trevor, R.I.G. Morrison, E. Nol, H.-U. Rösner, D. Schamel, H. Schekkerman, M.Y. Soloviev, P.S. Tomkovich, D.M. Tracy, I. Tulp, and L. Wennerberg. 2007. Effects of climate variation on the breeding ecology of Arctic shorebirds. – Meddelelser om Grønland Bioscience 59. Copenhagen, Danish Polar Center 2007. 48 pp. Morrison, R.I.G, McCaffery, B.J., Gill, R.E., Skagen, S.K., Jones, S.L., Page, G.W., Gratto-Trevor, C.L. & Andres, B.A. 2006. Population estimates of North American shorebirds, 2006. Wader Study Group Bull. 111:67–85. Neel, L. A. and W. G. Henry. 1997. Shorebirds in the Lahontan Valley, Nevada, USA: a case history of western Great Basin shorebirds. International Wader Studies 9: 15-19. North American Bird Conservation Initiative, U.S. Committee, 2010. The State of the Birds 2010 Report on Climate Change, United States of America. U.S. Department of the Interior: Washington, DC. Oring, L.W., L. Neel, K. E. Oring. 2000. Intermountain West Regional Shorebird Plan, version 1.0. Regional report of the U.S. Shorebird Conservation Plan. Manomet Center for Conservation Sciences., P.O. Box 1770, Manomet, MA 02345 (www.manomet.org) Pampush, G.J. and R.G. Anthony. 1993. Nest success, habitat utilization and nest-site selection of Long-billed Curlews in the Columbia Basin, Oregon. Condor 95: 957967. Paul, D.S., and A.E. Manning. 2002. Great Salt Lake Waterbird Survey Five-Year Report (1997–2001). Publication Number 08-38. Utah Division of Wildlife Resources, Salt Lake City. Paullin, D. G., C. D. Littlefield, and R. E. Vorderstrasse. 1977. Malheur-Harney Lakes Basin Study, Oregon, Report 1. U. S. Fish and Wildlife Service, Unpubl. Report. Portland, OR. 47 pp Paulson, D. 1993. Shorebirds of the Pacific Northwest. Seattle: University of Washington Press.

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LITERATURE CITED Robinson, J.A., J.M. Reed, J.P. Skorupa, and L.W. Oring. 1999. Black-necked Stilt (Himantopus mexicanus), in The Birds of North America (A. Poole and F. Gill, eds.), no. 449. Acad. Nat. Sci., Philadelphia. America.

U.S. Fish and Wildlife Service (USFWS). 2003. Endangered and threatened wildlife and plants: Withdrawal of the proposed rule to list the Mountain Plover as threatened. Federal Register 68:53083.

Shuford, W.D, G.W. Page, and L. E. Stenzel. 2002. Patterns of Distribution and abundance of migratory shorebirds in the Intermountain West of the United States. Western Birds 33:134 – 174.

USFWS. 2008. Birds of Conservation Concern 2008. United States Department of Interior, Fish and Wildlife Service, Division of Migratory Bird Management, Arlington, Virginia. 85 pp. [Online version available at http://www.fws.gov/migratorybirds/

Shuford, W.D., D.L. Thomson, D.M. Mauser, and J. Beckstrand. 2006. Abundance and distribution of nongame waterbirds in the Klamath Basin of Oregon and California from comprehensive surveys in 2003 and 2004. PRBO Conservation Science, 4990 Shoreline Highway 1, Stinson Beach, CA.

Vickery, P. D., D. E. Blanco, and B. López-Lanús. 2010. Conservation Plan for the Upland Sandpiper (Bartramia longicauda). Version 1.1. Manomet Center for Conservation Sciences, Manomet, Massachusetts.

Thomas, S. 2005. Recent Intermountain West conservation Projects that Benefit Shorebirds: July 2005. U. S. Shorebird Conservation Plan: Regional Reports. U.S. Fish and Wildlife Service, Division of Migratory Bird Management. Online: http://www.fws.gov/shorebirdplan/ RegionalShorebird/RegionalReports.htm

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APPENDIX A. SHOREBIRD SCIENCE TEAM MEMBERS • Brad Andres, U.S. Fish and Wildlife Service • Daniel Casey, American Bird Conservancy • Wendell Gilgert, Natural Resources Conservation Service • Suzanne Fellows, U.S. Fish and Wildlife Service • Gary Ivey, International Crane Foundation • Dave Mauser, U.S. Fish and Wildlife Service • Colleen Moulton, Idaho Department of Fish and Game • Larry Neel, Nevada Department of Wildlife • Don Paul, AvianWest, Inc. • Mark Petrie, Ducks Unlimited, Inc. • Bridget Olson, U.S. Fish and Wildlife Service • Dave Shuford, PRBO Conservation Science • Kelli Stone, Two Birds One Stone LLC • Sue Thomas, U.S. Fish and Wildlife Service

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APPENDIX B. STATUS OF SHOREBIRD SPECIES Status of shorebird species identified through regional conservation scores in the U.S. Shorebird Conservation Plan

nonbreeding season. Wilsonâ&#x20AC;&#x2122;s Phalarope are found in high concentrations at a small number of large saline lakes in the JV on migration, thus their Nonbreeding Distribution = 5. Conservation of foraging resources (e.g. brine flies and brine shrimp) at those sites would be very beneficial for this species. The specific scores for shorebirds in the Intermountain West are provided below.

These scores can provide a means for partners to assess conservation activities for the highest return on conservation dollars. For instance, a common passage shorebird in the JV with a high TN score coupled with a high score for ND would be an excellent species for conservation measures during the passage or

SPECIES

1

PT

RA

TB

TN

BD

ND

CS

Black -bellied Plover

5

3

2

2

2

1

3

Snowy Plover

5

5

4

4

3

4

5

Semipalmated Plover

3

3

2

2

1

1

2

Killdeer

5

1

3

3

1

2

3

Mountain Plover

5

5

4

4

5

4

5

Black-necked Stilt

3

3

3

2

1

2

2

American Avocet

3

2

3

4

2

3

3

Greater Yellowlegs

3

4

2

2

2

1

3

Lesser Yellowlegs

3

2

2

3

2

1

2

Solitary Sandpiper

3

4

4

2

3

2

4

Willet

3

3

3

3

3

3

2

Spotted Sandpiper

3

3

2

2

1

1

2

Upland Sandpiper

2

2

2

4

2

3

2

Whimbrel

5

4

2

2

3

2

4

Long-billed Curlew

5

5

4

4

3

3

5

Marbled Godwit

4

3

4

4

3

3

4

Red Knot

5

2

2

4

3

3

4

Sanderling

5

2

2

4

2

1

4

Semipalmated Sandpiper

5

1

2

3

3

3

3

Western Sandpiper

3

1

2

4

4

2

3

Least Sandpiper

5

2

2

2

2

2

3

Baird's Sandpiper

3

2

2

2

3

3

2

Pectoral Sandpiper

3

2

2

3

2

3

2

Dunlin

5

2

2

3

2

3

3

Stilt Sandpiper

3

3

3

4

3

3

3

Short-billed Dowitcher

5

2

2

4

3

2

4

Long-billed Dowitcher

2

2

2

3

4

3

2

Wilson's Snipe

5

1

3

2

1

2

3

Wilson's Phalarope

4

1

3

4

2

5

4

Red-necked Phalarope

4

1

2

3

1

3

3

From Bird Conservation Region Area Importance Scores at www.fws.gov/shorebirdplan/RegionalShorebird.htm

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APPENDIX B. STATUS OF SHOREBIRD SPECIES Population Trend (PT) – Represents an assessment of available information on population trends and to estimate broad categories of population decline. They range from 5 = species with documented population decline to 1 = Significant population increase.

Breeding Distribution (BD) - This variable ranks the size of the breeding range for species that breed in North America, and only applies during the actual breeding season (5 = <2.5% of North America to 1 = >20% of North America).

Relative Abundance (RA) – An assessment of population size (5 = <25,000 to 1 = >1,000,000)

Non-breeding Distribution (ND) - This variable refers to distribution during the non-breeding season and rates the relative risks associated with having a smaller absolute range size during the non-breeding season (5 = Highly restricted or very restricted coastal areas, or interior range to 1 = Very widespread).

Threats During the Breeding Season (TB) - Ranks known threats. Also indicates limited knowledge available for determining threats to most shorebirds (5 = Known threats occurring and documented to 1 = Demonstrably secure). Threats During Non-breeding Season (TN) - This score applies the criteria listed above for TB scores to the migration and over-wintering period and also considers concentration risks (5 = Concentration results in actual risk to 1 = Demonstrably secure).

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Conservation Score (CS) – This score takes into consideration all scores presented above. (5 = all species liste as threatened or endangered nationally to 1= no apparent risk of population decline).

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APPENDIX C. COMMON & SCIENTIFIC NAMES OF SHOREBIRD SPECIES LISTED IN THIS DOCUMENT COMMON NAME

SCIENTIFIC NAME

Black-bellied Plover

Pluvialis squatarola squatarola

Snowy Plover

Charadrius alexandrinus nivosus (Interior)

Semipalmated Plover

Charadrius semipalmatus

Killdeer

Charadrius vociferous vociferous

Mountain Plover

Charadrius montanus

Black-necked Stilt

Himantopus mexicanus mexicanus

American Avocet

Recurvirostra americana

Greater Yellowlegs

Tringa melanoleuca

Lesser Yellowlegs

Tringa flavipes

Solitary Sandpiper

Tringa solitara solitaria/cinnamomea

Spotted Sandpiper

Actitis macularia

Willet

Catoptrophorus semipalmatus inornatus

Upland Sandpiper

Batramia longicauda

Long-billed Curlew

Numenius americanus

Whimbrel

Numenius phaeopus rufiventris

Marbled Godwit

Limosa fedoa fedoa (Plains)

Red Knot

Calidris canutus roselarri

Sanderling

Calidris alba

Semipalmated Sandpiper

Calidris pusilla

Western Sandpiper

Calidris mauri

Least Sandpiper

Calidris minutilla

Baird's Sandpiper

Calidris bairdii

Pectoral Sandpiper

Calidris melanotos

Dunlin

Calidris alpina pacifica

Stilt Sandpiper

Calidris himantopus

Short-billed Dowitcher

Limnodromus griseus caurinus

Long-billed Dowitcher

Limnodromus scolopaceus

Wilson's Snipe

Gallinago delicata

Wilson's Phalarope

Phalaropus tricolor

Red-necked Phalarope

Phalaropus lobatus

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Cha pte r Six

Wa t e r b i r d s

Pr incipa l Autho r s: Ta r a Zimme r ma n, G a r y Ivey, a nd Jo sh Ve st

Photo by Utah Division of Wildlife Resources


Inside this Chapter Introduction........................................................................................................................... 6.3

Wa t e r b i r d s

Waterbirds & The Intermountain West Region.. ..................................................................... 6.6 Overview of Planning Approach............................................................................................ 6.9 Waterbird Population Status & Trends.. ............................................................................... 6.10 •

Eared Grebe................................................................................................................... 6.12

Double-Crested Cormorant............................................................................................. 6.12

White-faced Ibis............................................................................................................. 6.13

Sandhill Cranes.............................................................................................................. 6.13

Caspian Tern.................................................................................................................. 6.15

Threats & Limiting Factors.................................................................................................. 6.16 •

Loss and Degradation of Wetland Habitat........................................................................ 6.16

Water Supply and Security.............................................................................................. 6.16

Water Quality.. ................................................................................................................ 6.18

Loss of Foraging Habitat................................................................................................. 6.18

Climate Change.............................................................................................................. 6.18

Population Estimates & Objectives..................................................................................... 6.20 Focal Species...................................................................................................................... 6.21 •

Focal Species Approach................................................................................................. 6.21

Focal Species and Conservation Planning....................................................................... 6.24

Focal Species Profiles.. ................................................................................................... 6.25

Population Inventory & Monitoring...................................................................................... 6.28 •

Western Colonial Waterbird Survey, 2009–2011............................................................... 6.28

North American Marsh Bird Monitoring............................................................................ 6.28

Continental Marsh Bird Monitoring Pilot Study.. ............................................................... 6.29

Periodic or Annual Waterbird Surveys.. ............................................................................ 6.29

Species-Specific Surveys.. .............................................................................................. 6.30

Next Steps........................................................................................................................... 6.32 Literature Cited................................................................................................................... 6.33 Appendix A. Waterbird Science Team Members.................................................................. 6.39 Appendix B. Double-Crested Cormorant Breeding Pairs in the Intermountain West.......... 6.40 Appendix C. Caspian Tern Breeding Pairs in the Intermountain West.. ............................... 6.41 Appendix D. White-faced Ibis Breeding Pairs in the Intermountain West........................... 6.43 Appendix E. Focal Area Profiles – Descriptions & Threats.................................................. 6.46 Appendix F. Literature Cited in Appendices........................................................................ 6.64

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INTRODUCTION

Photo by Rio de la Vista

The goal of the Waterbird chapter is to build upon the IWJV 2005 Coordinated Bird Conservation Plan (2005 Implementation Plan) by identifying priority waterbird species within the Intermountain West region and a suite of waterbird focal species from which to develop a regional science-based framework for waterbird conservation. Regional waterbird abundance and distribution data were updated with the most recent and available data which will inform the future derivation of population objectives to support conservation planning. For the purposes of this chapter, waterbirds are defined as wetland dependent colonial, semi-colonial, and solitary nesting species such as loons, grebes, bitterns, herons, egrets, cranes, rails, gulls and terns. The framework for this chapter is established in continental and regional waterbird conservation plans. Recognizing that conservation is most effective when planned and implemented at the regional and local scales, The North American Waterbird Conservation Plan (NAWCP; Kushlan et. al. 2002) delineated 16 regional waterbird conservation planning areas within North America. The NAWCP also provides conservation assessments, population estimates, and identifies colonialnesting waterbird species of conservation concern at continental and hemispheric scales. A 2006 supplement to the NAWCP: the Conservation Status Assessment and Categories of Concern for Solitary-Nesting Waterbirds (www.waterbirdconservation.org/assessment.html) assesses and prioritizes the conservation status of 43 species of solitary-nesting waterbirds. The NAWCP and

6.3

species assessments provide a common framework to facilitate coordinated waterbird conservation across North America. The Intermountain West Waterbird Conservation Plan (IWWCP; Ivey and Herziger 2006; http://www. waterbirdconservation.org/intermountain_west.html ) serves as the biological foundation for IWJV waterbird conservation. Thirty-eight species of waterbirds representing nine families regularly utilize the IWJV area as year-round or seasonal habitat (Table 1). The IWWCP plan provides a foundation for biological planning for these waterbirds. It prioritizes breeding and migrant waterbird species at the regional scale; provides data on waterbird distribution and abundance; sets preliminary waterbird population objectives by Bird Conservation Region (BCR) and state; identifies important waterbird habitats in the region; and provides site-specific information on nine key waterbird sites with critical conservation needs. The IWJV encompasses nearly all of the Intermountain West Regional Waterbird Planning Area. The IWJVâ&#x20AC;&#x2122;s 2013 Implementation Plan represents an important, incremental step toward strategic conservation planning for waterbirds as it provides the foundation for biological planning. However, actions recommended to conserve important key sites and Bird Habitat Conservation Areas (BHCA) identified in the 2005 Implementation Plan and IWWCP (Ivey and Herziger 2006) will continue to benefit migratory bird populations in the Intermountain West.

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INTRODUCTION

Nesting Strategy

Chihuahuan Desert BCR 35

Sierra Madre Occidental BCR 34

Sonoran Mohave Deserts BCR 33

SPECIES

So. Rockies -Colorado Plateau BCR 16

Great Basin BCR 9

No. Rockies BCR 10

Table 1 W  aterbird Seasonal occurrence, relative abundance1 and nesting strategy2 in the Intermountain West Joint Venture listed by Bird Conservation Region (BCR).

Pacific Loon

m, w

m, w

m

m, w

m,w

m, w

S

Common Loon

b, m, w

b, m

m,w

m, w

m,w

m,w

S

Pied-billed Grebe

b, m, w

b, m, w

b, m, w

b, m, w

b, m, w

b, m, w

S

Horned Grebe

b, m

m

b, m

m, w

-

m, w

S

Red-necked Grebe

b, m

b, m

-

-

-

-

SC

Eared Grebe

b, M

b, m

b, m, w

m, w

b, m, w

m, w

C

Western Grebe

B, m, w

b, m, w

b, m

m, w

b, m

b, m, w

C

Clark’s Grebe

B, m, w

b, m, w

b, m

b, m, w

b, m

b, m, w

C

American White Pelican

B, M

b, m

b, m

m, w

m, w

m, w

C

Neotropic Cormorant

-

-

m

-

-

b, m, w

C

Double-crested Cormorant

b, m, w

b, m

b, m

b, m, w

b, m, w

m, w

C

American Bittern

b, m, w

b, m

b, m

m, w

m

m, w

S

Least Bittern

b, m

-

-

b, m

b, m

b, m

S

Great Blue Heron

b, m, w

b, m, w

b, m, w

b, m, w

b, m, w

b, m, w

C

Great Egret

b, m, w

m

m

m

b, m, w

C

Snowy Egret

b, m

b

b, m

m

m

b, m

C

Cattle Egret

b, m

b

b, m

m

m

b, m

C

Green Heron

b ,m

-

b, m

b, m

b, m

b, m, w

SC

Black-crowned Night Heron

B, m

b

b, m, w

b, m, w

b, m, w

b, m, w

C

White-faced Ibis

B, m

b, m

B, m

m

m

m

C

Yuma Clapper Rail3

-

-

-

b

-

-

S

Yellow Rail

B, m, w

-

-

-

-

-

S

Black Rail4

-

-

-

b3

-

-

S

Virginia Rail

b, m, w

b, m

b, m, w

b, m, w

b, m

b, m, w

S

Sora

b, m w

b, m

b, m, w

b, m, w

b, m

b, m, w

S

Common Moorhen

b

-

b, m

b, m

-

b, m, w

S

American Coot

b, m, w

b, m

b, m, w

b, m, w

b, m, w

b, m, w

S

Greater Sandhill Crane – LCRVP5

B, M

b

-

-

S

Greater Sandhill Crane – CVP5

B, M

b

-

-

S

Greater Sandhill Crane – RMP5

B

B

b, M

-

Lesser Sandhill Crane – PFP6

M, w

m

m

-

m

Lesser Sandhill Crane - MCP6

m, w

M, W

S

-

m, w

M, W

S

S

Franklin’s Gull

b, m

b, m

b, m

m

m

w

C

Bonaparte’s Gull

m, w

m

m

m

m

m

S

Ring-billed Gull

b, m, w

b, m, w

m, w

m, w

m

m

C

California Gull

B, m, w

b, m, w

b, m, w

m

m

m

C

Herring Gull

m, w

m, w

m

-

-

m, w

C

Glaucous-winged Gull

b, w

-

-

-

-

-

C

Caspian Tern

b, m

b, m

m

b

m

m

C

Common Tern

m

b, m

-

-

-

m

C

Forster’s Tern

B, m

b, m

b, m

b, m

m

m

C

Black Tern

b, m

b, m

b, m

m

m

m

SC

6.4

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INTRODUCTION 1. Relative Abundance Indicators: B, M, W – high concentrations, region is extremely important to the species relative to most other regions (Regional BCR AI = 5 or 4 – 25% - 50% of N. American population); B, M, W – common or locally abundant, region is important to the species (Regional BCR AI = 3; with 10% - 24% of N. American population) ; b, m, w – common to fairly uncommon, region is within the species range but species occurs in low abundance relative to other regions (Regional AI = 2 or 1 (<1 – 9% of NA population); b, m, w – status as breeder, migrant, or wintering bird is known but abundance relative to other regions is unknown. 2. Nesting Strategy - Most typical nesting strategy: C= colonial; S= solitary; SC= semi-colonial

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3. Yuma Clapper Rail – Occurs in Muddy and Virgin River valleys, NV. Breeding confirmed in Big Marsh, Clark, County NV in 2001 (Floyd 2007). 4. Black Rail – Reported to occur along the Virgin River, Clark County NV in July 2003 but breeding not confirmed (Floyd 2007). 5. Greater Sandhill Crane Population Designations: CVP – Central Valley Population; LCRVP – Lower Colorado River Valley Population; RMP – Rocky Mountain Population; PFP – Pacific Flyway population; MCP – Mid Continent Population. 6. Lesser Sandhill Crane Population Designations: PFP – Pacific Flyway Population; MCP – Mid- continent Population.

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WATERBIRDS & THE INTERMOUNTAIN WEST REGION The IWJV is vast, stretching from Canada to Mexico, and ranging in elevation from 282 feet below sea level to 14,775 feet above sea level. The region is bounded by the Sierra Nevada and Cascades mountains on the west and the Rocky Mountains on the east. With more than 13.4 million acres of aquatic and wetland habitat types, this unique area is characterized by a diverse assemblage of saline ecosystems, freshwater marshes, deep water lakes and reservoirs, agricultural lands, and riparian habitats. Waterbirds occupy the full spectrum of these habitats to meet their requirements for breeding, migrating, and wintering. The IWWCP identifies the following important waterbird habitat types, key sites, and their significance to waterbirds:

in implementation plans developed by other Joint Ventures (i.e., Pacific Coast, Central Valley and Playa Lakes JVs).

Saline Lakes The large, terminal, hyper-saline lakes in the IWJV are renowned for their unique biographic features and significance to wetland-dependant avifauna. Important sites include Mono Lake, California; Great Salt Lake, Utah, and Lake Abert, Harney Lake, and Summer Lake in eastern Oregon (Jehl 1994, Ivey and Herziger 2006). These sites provide an abundance of brine shrimp (Artemia spp.) and brine flies (Ephydra spp.), both critical food resources to various waterbird species during breeding, migration, staging, and molting life-cycle stages. Although the overall number of hyper-saline lakes is small, they support enormous concentrations of waterbirds during key stages of their life cycle. Mono Lake and Great Salt Lake host the largest California Gull rookeries in the world with more than 130,000 breeding adults (Cooper 2004). These two sites alone support millions of Eared Grebes that stage and molt in the fall (Boyd and Jehl 1998; Neill et al. 2009).

Freshwater Wetlands

Figure 1 M  ap of the Intermountain West Joint Venture Area, Bird Conservation Region and State Boundaries.

The IWJV encompasses all or portions of 11 western states, the entire U.S. portions of BCR 9 (Great Basin) and 10 (Northern Rockies), and nearly all of BCR 16 (Southern Rockies; NABCI; Fig. 1). Portions of the Sonoran and Mojave Deserts, Sierra Madre Occidental, Chihuahuan Desert, Pacific Rainforest, Sierra Nevada, and Shortgrass Prairie BCRs are also encompassed by the IWJV. For planning purposes, the latter three BCRs were not addressed because they comprise relatively small portions of the IWJV or because these areas are addressed 6.6

In contrast to the comparatively few but critical saline lakes, lies an extended network of discrete freshwater marsh habitats dispersed throughout the IWJV landscape. These sites support waterbirds year-round including American White Pelican, Double-crested Cormorant, Greater Sandhill Crane, Sora, American Bittern, Virginia Rail, and numerous species of grebes, herons, egrets, gulls, and terns. Many of these species exhibit sitefidelity, occupying the same locations in multiple years. Yet waterbird colony locations and occupancy can change in response to site-specific and regional habitat conditions that fluctuate with short and long-term flood and drought cycles. Species such as White-faced Ibis have adapted to this variability by developing a nomadic breeding strategy at the landscape scale responding to dramatic shifts in both seasonal and annual wetland habitat conditions (Jehl 1994, Earnst et al. 1998, Haig et al. 1998). Other waterbirds, such as Franklinâ&#x20AC;&#x2122;s Gulls exhibit a similar strategy, and their colonies are often associated with those of White-faced Ibis. The extended network of semi-permanent wetlands dispersed across the arid west is critical to the reproductive success and long-term population viability of waterbirds throughout the west. Seasonal wetlands and wet meadows in the region serve as primary breeding and migration habitat for several subspecies and populations of waterbirds of particular management concern. Approximately 90% of

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WATERBIRDS & THE INTERMOUNTAIN WEST REGION the three western Greater Sandhill Crane populations (Lower Colorado River Valley Population [LCRVP]; Rocky Mountain Population [RMP]; and Central Valley Population [CVP]) breed within the wet meadows and seasonal wetlands in the Great Basin and Northern Rockies BCRs. The montane meadows of south central Oregon have recently been found to support nearly the entire population of Yellow Rails in the western United States. Yellow Rails in Oregon were considered extirpated by the mid-1900’s (AOU 1983) but were rediscovered in the 1980’s (Stern et al.. 1993). Currently thought to number between 400 and 1,000 birds, the western population is largely confined to the Klamath Basin and Great Basin wetlands of Oregon in the summer, and is thought to winter in marshes of coastal northern California (Lundsten and Popper 2002, Bookhout 1995, Popper and Stern 2000).

Deep Water Lakes and Reservoirs Construction of dams and other water projects in the IWJV has created open water habitats beneficial to breeding, migrating, wintering and roosting waterbirds. Pelicans, cormorants, loons, and grebes depend on deep water lakes and reservoirs to meet their year-round habitat requirements. Reservoirs with nesting islands and an abundance of fish support important breeding colonies of pelicans, terns and, gulls (e.g. Blackfoot Reservoir, Idaho and Clear Lake National Wildlife Refuge (NWR), California). Other natural lakes and reservoirs important to waterbirds identified in the IWJV include Eagle Lake; Goose Lake and Lake Almanor in California; Upper Klamath Lake in Oregon; and Lake Cascade and Lake Lowell (Deer Flat NWR) in Idaho.

Flood-Irrigated Agricultural Fields Flood-irrigated agricultural fields and flooded pastures, often occurring adjacent to wetlands, provide important foraging habitat for many waterbirds including ibises, herons, egrets, cranes, rails, and gulls during the breeding, migration, and winter seasons. In Nevada, ibises fed in irrigated alfalfa fields 86% of the time throughout the early summer, and by late summer they fed exclusively in these irrigated fields (Bray and Klebanow 1988). Virginia Rails and Soras use this habitat for post-breeding and brood-rearing life stages (Johnson and Dinsmore 1986). The entire management populations of Greater and Lesser Sandhill Cranes that migrate through the Pacific Flyway,

6.7

largely within the IWJV, rely on croplands, pasturelands, hayfields, and seasonal wetlands in the IWJV during both fall and spring migrations (Tacha et al. 1992; Pacific Flyway Committee 1983; Pacific and Central Flyway Committees 2007).

Riparian Riparian habitats in the IWJV range from broad deciduous tree and shrub flood-plain vegetation to narrow stringers of tamarisk in lowland desert habitats. Tree and shrublined rivers, streams, springs and ponds are primary habitat for nesting herons, cormorants, and egrets. Gallery riparian forests are particularly important to herons and cormorants. Vegetated islands in river mouths and braided river channels offer protected nesting habitat for tree and shrub nesters, and islands barren of vegetation provide the requisite predator-free breeding habitat for ground-nesting waterbirds such as terns and gulls. When riparian borders occur in combination with freshwater wetland habitat types, these ecosystems can support a higher number and diversity of waterbird species.

Key Sites Ivey and Herziger (2006) identified 44 individual wetland sites as very important to waterbirds within the Intermountain West (Fig. 2; IWWCP). Many of these function as discrete oases for some species while also functioning as part of a linked network of wetlands critical to waterbird populations at the larger landscape scale. All of these sites and other areas important to waterbirds are identified in the IWJV’s 2005 Implementation Plan and IWJV State Plans as BHCAs (note: these plans were developed by the IWJV’s 11 State Steering Committee, now referred to as State Conservation Partnerships). They include: Harney Basin and Lake Abert in Oregon; Klamath Basin and Goose Lake in Oregon and California; Lahontan Valley and Pyramid Lake in Nevada; Blackfoot Reservoir, Bear Lake NWR, and Grays Lake NWR in Idaho; Great Salt Lake in Utah; Centennial Valley in Montana; San Luis Valley in Colorado; Middle Rio Grande (including Bosque del Apache NWR) in New Mexico, and the White Mountain wetlands in Arizona. The protection and enhancement of BCHAs for migratory birds will continue to play an important role in conservation efforts for waterbirds addressed in this strategy and for all bird conservation.

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WATERBIRDS & THE INTERMOUNTAIN WEST REGION

Figure 2 Key Wetland sites identified in the Intermountain West Waterbird Conservation Plan (Ivey and Herziger 2006).

6.8

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OVERVIEW OF PLANNING APPROACH A Waterbird Science Team (WST) comprised of biologists with expertise in waterbird conservation in the Intermountain West convened to develop and guide this Strategy (Appendix A). The WST reviewed priority species, population estimates, population objectives, conservation assessments, and key site conservation strategies identified in the IWWCP and other available sources. When possible, waterbird population estimates and objectives were updated to reflect the current state of information available to support planning. A suite of waterbirds representing IWJV wetland habitat types, nest site attributes, and foraging guilds were identified as Focal Species for future conservation planning purposes. A subset of geographic areas of known significance to focal species, or those with significant concentrations of waterbirds (see Ivey and Herziger 2006) were identified as Focal Areas appropriate for future IWJV waterbird conservation planning at a sub-BCR scale.

Photo by Gar y Ivey

6.9

State-of-the-art conservation planning incorporates the use of population-habitat models and geospatial data to link population and habitat goals. Ideally, this level of planning would utilize knowledge of the population status and trends, habitat affiliations, limiting factors, and spatial and temporal characteristics of the species and landscape of interest (Will et al. 2005, USFWS 2006). The use of population-habitat modeling and a focal species approach to conservation also requires many assumptions (Caro and Oâ&#x20AC;&#x2122;Doherty 1998, Fleishman et al. 2000, Chase and Guepel 2005). This is particularly true for waterbirds in the Intermountain West because information and data necessary to support biological planning is severely lacking or limited; consequently, our capacity to conduct science-based conservation planning for western waterbirds is similarly challenged. Nonetheless, to initiate the conservation planning process, we identify a subset of focal species and landscapes (Focal Areas) deemed most appropriate for initial IWJV conservation planning for waterbirds. Improvements and advances in population monitoring, wetland inventory, and a better understanding of habitat affiliations, threats, limiting factors, and the spatial and temporal scales of western waterbird populations in the Intermountain West will provide the means to achieve strategic conservation for focal waterbirds in future plan updates. In consideration of data limitation and the limitations inherent to the use of an umbrella or focal-species approach to landscape scale restoration and protection (see Fleishman et al. 2001, Chase and Guepel 2005, Lindenmayer et al. 2006) the information in this plan is intended to supplement, not replace, the conservation goals and strategies identified in the IWWCP and 2005 IWJV Implementation Plan. The achievement of BHCA goals and wetland habitat acreage objectives at those sites currently documented to support significant waterbird communities (i.e., key sites) will continue to facilitate important habitat enhancement and restoration for waterbirds in the Intermountain West. In this manner, the IWJV will implement a range of approaches to waterbird habitat conservation, while continuing to improve the base of information necessary to advance conservation strategies for waterbirds in future plan updates. As such, this strategy serves as an intermediate step in the development of explicit conservation targets for waterbirds in the Intermountain West.

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WATERBIRD POPULATION STATUS & TRENDS

Photo by Gar y Ivey

Expert opinion and data from local, state, regional and national population monitoring programs were considered and compiled in the species conservation assessment process documented in the regional IWWCP (Ivey and Herziger 2006). For breeding waterbirds, IWWCP species priorities were identified using a modified conservation assessment process based on the Partners in Flight Species Assessment (Panjabi et al. 2005). Migrant waterbirds were identified as high conservation concern in the IWWCP if a site within a BCR supported 10% or more of the North American population during migration or if specific threats were identified at primary staging sites. Of the 33 waterbird species that regularly breed in the IWJV, the regional IWWCP identified six colonialnesting and four solitary-nesting waterbirds as species of high concern: Western Grebe, Clark’s Grebe, American White Pelican, Snowy Egret, Franklin’s Gull, and Black Tern; and Common Loon, American Bittern, Yellow Rail, and Greater Sandhill Crane (CVP). Migrant or wintering populations of Eared Grebe, Lesser Sandhill Crane, and LCRVP, RMP and CVP migrant Greater Sandhill Crane are also identified as species of high conservation concern at the regional scale.

6.10

For most waterbirds, data on population sizes over time is unavailable or insufficient for the purpose of estimating population trends. The North American Breeding Bird Survey (BBS) long-term trend results (1966 – 2007) indicate significant increasing population trends (P< .05) for four waterbird species in the Western Region: Common Loon, Eared Grebe, Snowy Egret, and Green Heron (Table 2; Sauer et al. 2008). Because the BBS uses a roadside point-count survey technique, certain habitats and species such as wetlands and colonial waterbirds are under-sampled (Bystrack 1981, Robbins et al. 1986). BBS trend estimates for waterbirds are particularly subject to known BBS data deficiencies including small sample sizes, low relative abundance on survey routes, and imprecise trends (Sauer et al. 2008). Even species with reported significant trends may have data deficiencies that affect the credibility of regional estimates of trend. For example, Western Region BBS data collected during the breeding season indicate that the population of Eared Grebes significantly increased 1966-2007 and 1980-2007 (Table 2); however, standardized species-specific annual monitoring efforts conducted at two saline lakes in the Intermountain West that support 99% of this population during the fall indicate declining population trends for this waterbird (see next page).

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WATERBIRD POPULATION STATUS & TRENDS Table 2 N orth American Breeding Bird Survey Trend Results for Waterbirds the Western Region, 1966-2007 and 1980-2007. 1966â&#x20AC;&#x201C;2007 trends

SPECIES

TREND1

P2

N3

1980â&#x20AC;&#x201C;2007 trends

(95% CI)4

R.A.5

TREND

P

N

Common Loon

1.6

0.01

131

0.4

2.8

0.46

0.9

0.15

123

Pied-billed Grebe

0.7

0.54

231

-1.6

3.1

0.24

0.9

0.57

206

-2.8

0.06

75

-5.7

0

0.38

-4.2

0.04

63

Red-necked Grebe

0.3

0.69

80

-1.3

1.9

0.42

-0.3

0.75

78

Eared Grebe

3.7

0.03

95

0.5

6.8

1.05

4.1

0.05

80

American White Pelican

1.7

0.31

106

-1.6

5.1

2.13

2.8

0.05

101

Double-crested Cormorant

2.9

0.1

147

-0.5

6.3

0.54

1.9

0.55

141

American Bittern

-4.4

0

122

-6.4

-2.3

0.33

-2.3

0.26

105

Least Bittern

22.1

0.14

2

12.7

31.5

0.03

22.8

0.14

2

Great Blue Heron

-0.5

0.47

464

-1.9

0.9

0.53

-0.8

0.21

422

Great Egret

3.3

0.09

73

-0.5

7.2

0.68

2

0.26

70

Snowy Egret

2.9

0.01

54

0.8

4.9

0.45

4.2

0.11

50

Cattle Egret

3.2

0.35

23

-3.3

9.6

2.08

0.1

0.98

23

Green Heron

2.3

0.02

76

0.4

4.2

0.11

-0.3

0.73

74

Black-crowned. Night Heron

1.7

0.22

101

-1

4.4

0.18

-1.7

0.33

91

11.6

0

42

5.3

18

20.06

8.5

0

41

Virginia Rail

3.3

0.04

42

0.4

6.2

0.03

5.8

0.01

41

Sora

0.1

0.92

298

-1.2

1.3

0.91

-0.6

0.28

283

Common Moorhen

4.9

0.1

16

-0.4

10.2

0.13

4.2

0.15

14

American Coot

-0.7

0.24

383

-1.9

0.5

2.47

-1.2

0.04

345

Sandhill Crane

1.7

0.3

181

-1.5

4.9

0.98

0.9

0.42

178

Franklin's Gull

7.7

0.26

133

-5.7

21.2

17

10.2

0.16

120

Ring-billed Gull

0.7

0.54

260

-1.6

3.1

4.62

0.3

0.82

233

California Gull

-1.7

0.25

189

-4.7

1.2

3.91

0.5

0.84

174

Herring Gull

-1.6

0.07

18

-3.1

-0.1

0.91

-1.9

0.06

16

Western Gull

-1.3

0.57

21

-5.8

3.2

4

-0.5

0.86

19

Caspian Tern

0.8

0.61

59

-2.2

3.8

0.23

1.3

0.51

55

Common Tern

-5

0.15

33 -

11.5

1.6

0.51

-8

0.04

29

Forster's Tern

-1.1

0.48

50

-4.3

2

0.27

-1.2

0.51

44

Black Tern

-2.5

0.13

160

-5.7

0.7

2.15

-2.1

0.06

138

Horned Grebe

White-faced Ibis

1. Trend - Estimated trend, summarized as a % change/year. 2. P - Value indicates the statistical significance of the trend. P greater than 0.05 indicates that we cannot reject the null hypothesis that the trend is different from 3. N - Number of survey routes in the analysis. 4. (95% CI ) - 95% confidence interval for the trend estimate. Estimated as a constant rate of change in counts over time, with co-variables to adjust for differences in observer quality. Regional trends are estimated as a weighted average of the route trends

So u rc e - Sa u e r, J . R. , J . E . H i n e s , a n d J . F a l l o n . 2 0 0 8 . T h e N o r t h A m e r i c a n Bre e di n g Bi rd Su r v e y, Re s u l t s an d An al y s i s 1 9 6 6 - 2 0 0 7 . Ve r s i o n 5 . 1 5 . 2 0 0 8 . U SG S Pa t u x e n t Wi l dl i fe Re s e a rc h C e n t e r, L a u re l , M D ( U p d a t e d 1 5 M a y 2 0 0 1 ; h t t p : / / www. m b r-pwrc . u s g s . g o v / c g i -bi n / a t l a s a 9 9 .pl ? WE % 2 0 &2 &0 7

5. R. A - Relative abundance for the species, in birds/ route. An approximate measure of how many birds are seen on a route in the region.

6.11

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WATERBIRD POPULATION STATUS & TRENDS With few exceptions, trend estimates for waterbirds in the NAWCP and IWWCP necessarily relied on expert opinion and both published and unpublished literature. The majority of IWWCP population trend (PT) scores for waterbirds listed by BCRs and states were assigned as “unknown” or “historically declined and apparently recovered” (PT = 3). Population size and trend estimates are most notably lacking for bitterns, rails and other secretive marsh birds but even the more common and widespread colonial waterbirds such as Great Blue Heron and Black-crowned Night Heron lack reliable trend estimates for the western U.S., the IWJV region, and most states. Population trends are known for a few waterbird species of particular management concern. Standardized annual monitoring programs, periodic rangewide surveys, and comprehensive status reviews provide insight into population trends of RMP and LCRV Sandhill Cranes, Eared Grebes, Caspian Terns and Double-crested Cormorants:

Eared Grebe Over 99% of the Eared Grebes in North America stage at Mono Lake, California and Great Salt Lake, Utah during the fall (Jehl 1988, 1994). Surveys using an aerial-photo technique with a correction factor applied to account for birds that are present but submerged have been implemented at both of these sites for most years since 1997 (Boyd and Jehl 1998; Neill et al. 2010). Total abundance on Mono Lake has varied between 0.6 and 1.8 million birds annually with an average annual estimate of 1.14 million grebes for the 9 survey years between 1997 and 2010 (www.monobasinresearch.org/research/boyd. htm; Fig. 3). Estimates at Great Salt Lake averaged about 1.2 million birds for 13 survey years during this same period. A high count of 2.7 million birds at Great Salt Lake was recorded in 2006 but no survey was conducted at Mono Lake that year. Similar to observations on Mono Lake, Neill et al. (2009) noted the wide variation in estimates at Great Salt Lake with numbers swinging as much as one million in either direction of the average count. Steep population declines occur in association with El Nino events but population numbers rebound in subsequent years (Jehl 2002). Additionally, Eared Grebes populations may be sensitive to brine shrimp productivity at key staging sites (Belovsky et al. 2011). The total estimated number of fall-staging Eared Grebes in the IWJV ranged from a high of 3.3 million in 2001 to a low of about 1.0 million in 2004 corresponding with post-El Nino conditions. Overall, numbers appear to be declining over time at both staging sites. It is unknown if 6.12

this decline represents a range-wide population decline, a change in the peak timing of the fall migration, or changing environmental conditions such as water levels or abundance of prey resources at staging areas.

Figure 3 N  umbers of Eared Grebes staging at Mono Lake, California and Great Salt Lake, Utah 1977–2010. Derived from: www.monobasinresearch.org/ research/boyd.htm; S. Boyd, Canadian Wildlife Service, Pacific Science Research Center and the CDFG; Neill et. al. 2009, GSL Ecosystem Program, Utah Division of Wildlife Resources; http:// ggweather.com/enso/years.htm

Double-Crested Cormorant Adkins and Roby (2010) defined the Western Population of Double-crested Cormorants as birds breeding in southern British Columbia and all U.S. states west of the Continental Divide. In 2009, they estimated this breeding population at 29,240 breeding pairs with about 18% located in breeding colonies within the IWJV. Until 2009, Double-crested Cormorants in the Intermountain West were monitored sporadically and incompletely. Data is available for some sites in 1998, 1999 and 2003–2009 (Appendix B), and this information provides some insight into cormorant distribution and abundance. In recent years, southeastern Idaho, the Columbia River Plateau in Washington, and southern Oregon northeastern California (SONEC) supported the majority of nesting cormorants in the Intermountain West. The number and location of colonies in these areas fluctuated annually and colony sizes ranged from 48 to just over 1,600 nesting pairs. The number of breeding pairs in Idaho may have increased 2005–2009 with up to 11 colony sites and a high count of 1,163 pairs in 2009. However, these increasing numbers could also be attributed to improvements and expansion of waterbird

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WATERBIRD POPULATION STATUS & TRENDS monitoring in Idaho implemented 2005–2009 (see Moulton 2005–2009). During this same period, numbers of breeding cormorants in the Columbia Plateau of Washington remained relatively stable, fluctuating from a high of 1,554 in 2006 at five colony sites to a low of 1,196 in 2009 at four colony sites (Roby and Adkins 2010). In the SONEC area, the Upper Klamath Marsh, Lower Klamath NWR, Tule Lake NWR and Clear Lake NWR support most of the cormorants that breed in this region. Recent drought conditions in the Klamath Basin eliminated nesting islands and reduced foraging habitat at many known colony sites; thus, population levels in 2009 were lower than in most years (Shuford and Henderson 2010). The peak Double-Crested Cormorant count in the Klamath Basin occurred in 2003 when 1,603 breeding pairs were estimated (Shuford and Henderson 2010). In Nevada numbers of cormorants have declined from 1,677 pairs at 4 colony sites in 1999 to 660 breeding pairs at 6 colony sites in 2009 (Adkins and Roby 2010). In total, about 60 sites scattered across the IWJV have been colonized by cormorants but many are occupied infrequently. Double-crested Cormorants in the Intermountain West are subject to the effects of drought, recurrent flooding and stranding of colonies, and loss of foraging habitat due to agricultural withdrawals and runoff for irrigation purposes. These conditions likely limit the population growth of Double-crested Cormorants in the IWJV area.

White-faced Ibis Between the 1960s and 1970s the numbers of Whitefaced Ibises breeding in the Great Basin Region declined significantly (King et al. 1980; Steele 1980), presumably, from exposure to DDT on their wintering grounds in the interior of Mexico (Capen 1977, Henny 1997). Between 1985–1997, the Great Basin population rebounded and the number of breeding ibises nearly tripled from an estimated 7,500 pairs among 19 colonies in the mid-1980s to about 30,000 pairs at 40 sites in the late 1990s (Earnst et. al. 1998). Breeding distribution shifted radically over time in response to seasonal environmental conditions such as flood and drought (Earnst et al. 1998). In 1979-1980, the majority of ibises in the Intermountain West were breeding at Great Salt Lake; however, when marshes of the Great Salt Lake were flooded 1983–1989 ibis colony sites were submerged and ibis numbers there decreased approximatley 80%; (Jehl 1994). Concomitantly, numbers of breeding ibises increased at Malheur and Summer Lakes, Oregon as did colony sizes at the Stillwater and Carson Lakes areas of Nevada (Ivey et al. 1988, Jehl 1994). When drought conditions dried these areas 1987– 6.13

1992, nesting colonies failed but successful ibis colonies were re-established at Great Salt Lake (Ivey et al. 1988, Jehl 1994, Earnst 1998). Surveys conducted in 2009 and 2010 again documented significant population growth and redistribution of breeding White-faced Ibises in the IWJV compared to previous decades (Appendix C). All states in the IWJV region surveyed ibises as part of the Western Colonial Waterbird Survey (WCWS) in 2010 (USFWS 2011) with the exception of Utah where ibis colonies were surveyed in 2009. Preliminary results from these surveys documented about 67,000 pairs of ibises in 2010 and 23,600 pairs in Utah in 2009 for a combined total of about 90,600 pairs at 47 colony sites for the 2 year survey period (Appendix C). This is triple the number of breeding White-faced Ibises documented in the late 1990s. The core of the population now breeds in southeastern Idaho, followed by smaller numbers in SONEC (Lower Klamath NWR, California; Malheur NWR, and Goose Lake, Oregon) and the Great Salt Lake. The six active colonies in Idaho supported 44,250 nesting pairs representing nearly half of the total Intermountain West population of breeding ibises for the combined 2009-2010 survey period. When numbers of breeding ibises in southeastern Idaho are combined with those breeding at Bear River Migratory Bird Refuge, Utah and Cokeville Meadows, Wyoming (in the Bear River Basin) and Great Salt Lake, Utah, this tri-state region currently supports 65.3% of the total number of breeding ibises in the Intermountain West. Reasons for this recent redistribution are unclear but are likely related to drought conditions and forage availability at traditional colony sites. A landscape-scale analysis of ibis breeding and foraging habitat in current and historic key locations for this species (i.e. Southeast Idaho, SONEC, and Great Salt Lake and Lahontan Valley) will aid in informing conservation for this species.

Sandhill Cranes The Pacific Flyway Council established management plans for the RMP, CVP and LCRV populations of Greater Sandhill Cranes (1995, 1997 and 2007) and also for the Pacific Flyway Population (PFP) of Lesser Sandhill Cranes (Pacific Flyway Council 1983). These plans established population objectives and multistate cooperative monitoring programs that have been implemented annually since 1992 for RMP and 1998 for LCRV. Standardized monitoring programs have not been implemented for the CVP or PFP. The highest nesting concentrations of RMP Greater Sandhill Cranes occur in western Montana and Wyoming, eastern Idaho, northern Utah, and northwestern Colorado

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WATERBIRD POPULATION STATUS & TRENDS (Kruse 2011). The major spring and fall migration staging area for the RMP is the San Luis Valley Colorado, where virtually the entire population spends 3–4 months annually (Drewien and Bizeau 1974, Kauffeld 1982). Several important overnight stopovers are used by RMP cranes during spring and fall migration including Harts Basin and the Grand Valley, Colorado, and the Green River near Jensen to Ouray National Wildlife Refuge in Utah (Drewien and Bizeau 1974, Peterson and Drewien 1997) and Cochiti and Jemez reservoirs, New Mexico (Stahlecker 1992). Other important fall staging sites include the Teton Basin, Grays Lake, in Idaho, Eden Valley in Wyoming, and the Bear River Valley in Idaho, Utah and Wyoming (Drewien and Bizeau 1974, R. Drewien, pers. comm.). The 2010 standardized fall pre-migration count documented 21,064 RMP cranes with a 3-year average of 20,847 (Fig. 4). This is within the population objective established by the flyways of 17,000–21,000 for the RMP (Kruse 2011). Their principal wintering area is the Middle Rio Grande Valley, New Mexico. Smaller numbers winter in northeastern and southwestern New Mexico, southeastern Arizona, and the northern highlands of Mexico (Drewien and Bizeau 1974, Perkins and Brown 1981, Drewien et al. 1996). On winter areas, RMP cranes mix with the Mid-continent Population (MCP), and cannot be managed separately from them.

Figure 4 F  all pre-migration abundance indices for the Rocky Mountain population of Sandhill Cranes. Derived from Kruse et al. (2011).

The LCRVP of Greater Sandhill Cranes is comprised of cranes that breed primarily in northeastern Nevada, with smaller numbers in adjacent parts of Idaho and Utah (and presumably, Oregon) and winters in the Colorado River Valley of Arizona and Imperial Valley of California (Kruse et al. 2011). During spring and fall migration,

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the LCRVP stages in Ruby Valley, near Lund, and at Pahranagat NWR in Nevada. Since 1998, a standardized aerial cruise survey has been conducted to cover 4 primary LCRV winter concentration areas which are believed to support over 90% of the LCRV crane population: Cibola NWR, and adjacent Colorado River Indian Tribal areas in southwestern AZ; and smaller concentrations at Sonny Bono Salton Sea NWR and the Gila River, AZ (Kruse et al. 2011). The recent LCRVP survey results indicate a slight increase from 2,264 birds in 2010 to 2,415 birds in 2011. The 3-year average is 2,360 LCRVP cranes which is below the population objective of 2,500 (Fig. 5).

Figure 5 A  bundance indices for the wintering Lower Colorado River Valley Population of Sandhill Cranes in Arizona and California. Derived from Kruse et al. (2011).

The CVP breeds primarily in central and eastern Oregon and northeastern California. Malheur NWR supports the highest number of breeding pairs in these two states (Ivey and Herziger 2000), where major concentrations of breeding cranes occur in Harney and Lake Counties, Oregon, and Modoc County, California. A few pairs nest in central Washington, on and near Conboy Lake NWR in south-central Washington and several hundred pairs also breed in the interior of British Columbia (Pacific Flyway Council 1997). Important migrational staging areas include Malheur NWR, the Silvies Floodplain, Warner Basin, Summer Lake Wildlife Area and Langell Valley in Oregon; Lower Klamath and Modoc NWRs, and Honey Lake, Butte Valley, Shasta, and Ash Creek Wildlife Areas in California, and the Othello area, on Columbia NWR in Washington. Additionally, a few Greater Sandhill Cranes stage in southwest Idaho, near the communities of Letha and Parma; the latter site includes Idaho’s Fort Boise Wildlife Area. It is uncertain whether those birds are

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WATERBIRD POPULATION STATUS & TRENDS from the CVP or the LCRVP. They share these sites with migrating PFP Lesser Sandhill Cranes. The PFP of Lesser Sandhill Cranes numbers more than 30,000 birds that breed in south-central and south-west Alaska and migrates through the IWJV via California, Idaho, Oregon, and Washington during spring and fall. The most important staging site is located on Columbia NWR at Othello, Washington, where more than 90% of the population stops during spring migration. Important Oregon sites include the Silvies Floodplain in Harney County, Summer Lake Wildlife Area, and the Chewaucan, Goose Lake and Warner Basins. Major staging sites in California include Modoc NWR vicinity, Surprise Valley, and Lower Klamath NWR. PFP cranes winter outside of the IWJV, in the Central Valley of California, primarily in the Sacramento-San Joaquin Delta and the San Joaquin Valley near the cities of Modesto, Merced, and Pixley.

Caspian Tern Many colonies of breeding Caspian Terns in the Intermountain West area have been monitored annually by agency biologists and researchers since 1997. Surveys were incomplete, however, in most years and therefore

unsuitable for estimating population trends over time. Nevertheless, this information serves to identify and characterize tern distribution and relative abundance. Core breeding range for Caspian Terns in the Intermountain West includes colonies in the Mid-Columbia River and Columbia Basin Plateau, Washington; SONEC, and southeastern Idaho. Surveys in these areas were most complete in 2001, 2003, 2008 and 2009 (Appendix B). Numbers of breeding pairs in these 4 years ranged from a low of 1,161 pairs in 2003 to a high of 1,846 pairs in 2009, when the most comprehensive and complete survey of breeding pairs was implemented. The population in the IWJV is characterized by fluctuations in both colony locations and size as terns respond to annual variations in habitat conditions. Areas of highest concentration of breeding pairs shifted from northeastern California where numerous colonies were documented in the late 1970â&#x20AC;&#x2122;s to dispersed colonies in eastern Oregon, eastern Washington and Idaho in more recent years. Colonies in the Intermountain West have not experienced the rapid growth observed at the large colony on East Sand Island located in the Columbia River Estuary.

Photo by Colleen Moulton

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THREATS & LIMITING FACTORS

Primary Threats to Waterbirds in the Intermountain West Region •

Wetland Habitat Loss

Loss of water or modified flow regimes

Water Quality and Contaminants

Exotic Plant and Fish Species

Human Disturbance

C onflicts with other species ( I v e y a n d H e r z ige r, 2 0 0 6 )

Ivey and Herziger (2006) identified and reviewed primary threats and limiting factors for waterbird populations in the Intermountain West. Of greatest conservation concern are issues associated with wetland loss, declining water supply/delivery to wetland habitats, and poor water quality. In recent years, the effects of climate change on migratory birds have been a topic of increasing concern. Quantifying the effects of various anthropogenic and natural threats on waterbird populations is difficult; but, these threats cumulatively or individually can negatively impact waterbird abundance, distribution, and reproductive success at the site specific, regional, or range wide scale. Threats may also vary by individual species and these have been described and characterized for several waterbirds in the West including Double-crested Cormorants (Adkins and Roby 2010), Caspian Terns (Shuford and Craig 2002), and Black Terns (Shuford 1999). Below we summarize broad-scale threats to waterbirds: wetland loss; wetland water supply and security; water quality; and climate change. Regionspecific summaries of threats for five waterbird Focal Areas are presented in Appendix D.

Loss and Degradation of Wetland Habitat The IWWCP identifies one of the most important issues facing waterbird conservation in the Intermountain West as wetland loss. Between the time of initial European settlement and the mid-1980s, more than 50% of freshwater wetlands were lost in the states of Idaho, Nevada, and Colorado and 91% in California, though mostly in the Central Valley (Dahl 1990). Although the rate of wetland loss has slowed over time, the loss of freshwater emergent marsh habitat has continued (Dahl 2006).

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Ratti and Kadlec (1992) estimated that approximately 57% of wetlands in the Intermountain West had been lost to drainage associated with agriculture and development. Wetlands now cover only about 1% of the regions land area compared to 5% nationwide (Dahl 2006). The remaining wetlands are critical to waterbird populations at local, regional, and continental scales. Wetlands of the Great Basin support 38% of North America’s waterbird diversity (waterbirds, shorebirds, and waterfowl; Haig et al. 1998) and nearly the entire North American populations of breeding White-face Ibises, California Gulls, and migrant Eared Grebes (Jehl 2004; Engilis and Reid 1996). The Klamath, Harney, Lahontan, and Great Salt Lake Basins are of continental or regional significance to waterbirds such as pelicans, ibises, grebes and gulls (Shuford 2006; Shuford and Henderson 2010; G. Ivey, unpublished data). Wetlands in southeastern Idaho are emerging as an increasingly significant component of the network of Intermountain West sites that support breeding White-faced Ibises and Franklin’s Gulls (Moulton 2006, 2007). Unfortunately, information to assess the amount, distribution and quality of wetland habitats in most of the Intermountain West is inadequate or unavailable at this time (refer to Chapter 2 of the IWJV 2013 Implementation Plan). Updated USFWS National Wetlands Inventory (NWI) data is a critical need throughout the western United States. The lack of this baseline habitat data and paucity of standardized population monitoring for waterbirds continues to impede progress and effectiveness of waterbird conservation efforts in the West.

Water Supply and Security Historic and contemporary policies pertaining to the protection and use of water in the arid West prioritize agriculture and municipal uses over environmental uses such as wetland management for migratory birds (Downard 2010). In 1990, about 80% of the water diverted from streams in the western United States was used for agricultural purposes (Solly 1997). In 2005, the states of California, Idaho, Colorado and Montana combined accounted for 64% of all surface water withdrawals for irrigation nationwide (Kenny et al. 2009). These diversions and withdrawals, primarily from snow-melt dependant streams, can leave natural and managed wetlands dry mid-summer through fall when waterbirds require wetlands for breeding, fledging, post-breeding, and foraging, particularly in years experiencing drought conditions. Wetland complexes critical to western waterbird populations such as Mono Lake, California, Great Salt Lake, Utah, Lahontan Valley, Nevada and Klamath Basin, Oregon have all been subject to

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THREATS & LIMITING FACTORS significant declines in water supply due to diversions and withdrawals from inflow streams and tributaries, primarily for agricultural purposes (Jehl 1994, Ivey 2001, Downard 2010, Mono Lake Committee 2011).

Carson River system, Nevada until sufficiently wet conditions in 2005 recharged wetlands (Hill et al. 2007). Drought conditions in the West 2001–2002 and 2007–2009 were considered severe to extreme (Fig. 6).

Increasing competition for water supplies stemming from population growth in the Intermountain West is further taxing already limited water resources in the arid region. Between 2000 and 2010 the human population increased 21% in Idaho, 23% in Utah and 35% in Nevada (U.S. Census Bureau 2011). With population growth the demands for water for urban, municipal, and industrial uses escalate. Although surface runoff can account for up to 80% of lake and wetland recharge among the terminal lakes and wetlands in the Great Basin (Hoffman 1994), many wetland complexes in the Intermountain West are equally impacted by groundwater recharge (Engilis and Reid 1996). Ground water withdrawals to support growing urban and suburban communities in the west can also pose threats to wetlands, as recently documented at Great Salt Lake (Bishop et al. 2009, Yidana et al. 2010).

Whether the result of surface or ground water withdrawals for human uses, increasingly frequent and severe drought conditions, or combinations thereof, the lack of water to maintain and recharge wetland and associated foraging habitats (flooded agricultural fields and pastures) results in the loss of waterbird nesting and foraging habitat, nest abandonment, predation, and poor reproductive success. All of these conditions may vary among the many ecoregions encompassed by the IWJV. Maintaining an extensive network of varied wetland types (e.g., emergent wetlands, deep water lakes, saline systems) is critical to waterbirds in the Intermountain West that use this these habitats at the local and larger landscape scale.

Wetland protection provided by federal legislation such as Section 404 of the Clean Water Act, public ownership of wetlands (e.g. NWRs and WMAs), and restoration programs such as the Wetlands Reserve Program may protect or restore wetland habitat, but these mechanisms do not always protect water supplies or ensure water security to wetlands managed for migratory birds. Downard (2010) defined water security “the availability of a quantity of water, during most years, sufficient to support enough flooded or periodically flooded wetlands to meet habitat needs established by each refuge”. The lack of water security combined with the scarcity and annual variability of water in Intermountain West represent a substantial and ongoing threat to waterbirds in the region. Increasing demands for water from population growth, urban expansion, and power generation will further exacerbate future competition for water in the arid West. Availability of both surface and ground water has been further stressed by frequent and persistent droughts. Drought conditions in the West occurred during most years 2000–2011 (Fig. 6) with 2005-2006 and 2010- 2011 being the exceptions. At Great Salt Lake, drought conditions 1999–2004 reduced the amount of recharge to groundwater aquifers and the lake elevation declined to a near historic low in 2005 and 2008 (Yidana 2010). Drought conditions in 2001–2004 dried wetlands and eliminated nesting and feeding habitat for waterbirds in the Lower

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Figure 6 P  almer Drought Severity Index (PDSI1), Western Region October 1999–2011. 1PDSI Values: 0.49 PDSI = near normal; PDSI = -3.00 or below indicates severe to extreme drought; PDSI= +2.00 or above indicates moderately wet to extremely wet conditions. PDSI is displayed for the standard USGS Water Year: 1 October – 31 September. So urce: http://www7.ncdc.no aa.g o v/C DO / C DODi vi si o nal Sel ect.j sp; Accessed Octob er 2011.

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THREATS & LIMITING FACTORS Water Quality

Climate Change

Many of the major wetlands in the Intermountain West are located at the terminus of irrigated lands and are dependent upon agricultural return flows as a source of water (e.g. wetlands in Lahontan Valley, Nevada and Harney and Klamath Basins, Oregon). Typically, these return flows are higher in salt concentrations and nutrients, both of which can reduce productivity and diversity of wetlands. Reduced agricultural return flows due to increasing withdrawals for municipal or industrial use and conversion of flood irrigation to sprinkler systems can result in return flows insufficient for wetland habitat goals. Reduced return flows can also exacerbate contaminant problems, thereby threatening wildlife values of important areas (Ivey and Herziger 2006; Downard 2010). Drought conditions appeared to exacerbate the negative effects of mercury on productivity of Snowy Egrets at Lahontan Reservoir (Hoffman et al. 2009). Water quality and contaminants continues to be a concern at many Intermountain West wetlands most renowned for supporting large numbers of waterbirds including the Great Salt Lake, the Lower Carson River system including Lahontan Reservoir, Nevada and wetland complexes in the Klamath Basin, Oregon.

Profound changes in temperature, precipitation, snowpack, and spring melt dates have already occurred in the IWJV region and more change is predicted for the future. Projections of future climate change vary depending upon the type and scale of models employed to assess the consequences of increased greenhouse gases. Because the IWJV encompasses such a wide variety of ecoregions, the range and scope of predicted climate change also varies greatly across the region.

Loss of Foraging Habitat Loss of flood-irrigated agricultural lands is a potential threat to waterbirds that forage on these habitats. In the Lahonton Valley/Carson Sink region of Nevada, ibis colonies are associated with foraging sites in floodirrigated alfalfa (Bray and Klebenow 1988). Ibises nesting in the Klamath NWR foraged on surrounding private lands, mostly in flooded-irrigated pastures (Follansbee 1994). During the last 20 years, there has been a steady loss of these farmland habitats to housing and urbanization as well as the conversion of flood-irrigated agriculture to sprinkler irrigation. In the West, acres irrigated by surface irrigation methods declined by 16% whereas acres irrigated by sprinkler methods increased by 9% between 2000 and 2005 (Kenny et al. 2009). In the four southeastern Idaho counties within the Bear River Basin (Bannock, Bear Lake, Caribou, and Franklin Counties) about 1,300 acres of flooded agricultural lands per year have been converted to sprinkler irrigation, rendering these sites unsuitable as potential waterbird foraging habitat. Continued loss of flooded pasture and irrigated croplands is likely to continue as demands for land and water resources increase with population growth and shifts to more efficient sprinkler irrigation systems continue.

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• Temperature: The Great Basin has experienced regionwide increases in average temperatures of 0.5–1.1° F (Baldwin et al. 2003; Chambers 2008). Although the degree of temperature change has varied across the region, climatologists predict continuing temperature increases in Western North America ranging from about 4–11°F over the next century (IPCC 2007 Working Group I Report). Predictions of rising temperature are further supported by various downscale and regional circulation models for the Great Basin/Rocky Mountain Region, northeastern California, and the Sierra Nevada in eastern California (Baldwin 2003, Bell 2004; Reichler 2009; and PRBO 2011) • Precipitation: Increases in average annual precipitation ranging from 6–16% throughout most of the Great Basin have been documented with more frequent extreme high-precipitation years (Baldwin 2003; Chambers 2008). Conversely, the southern portions of Nevada, Utah, Colorado, Southeastern California and all portions of Arizona and Mexico within the Intermountain West are experiencing drying climatic conditions (Seager 2007). Recent investigations underscore the high uncertainty about the effects of climate change on annual precipitation across the Intermountain West. In some regions, models predict little change or drier conditions (Chambers 2008, PRBO 2011) while other regional models predict continued increases in precipitation (Baldwin 2003) or wetter winters and drier summers (Reichler 2009). However, portions of the arid southwest are predicted with growing certainty to be increasingly dry (Seager et al. 2007). • Snowpack and Snowmelt: Significant declines in snowpack and earlier spring snowmelts are well documented in the intermountain west (Mote 2005, Bedford and Douglas 2008). Consistency among climate models strongly suggest continued reductions in snowpack throughout most of the IWJV area, with the potential for extreme reductions of up to 70% in eastern and northeastern California (Mote 2005, PRBO 2011).

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THREATS & LIMITING FACTORS The documented effects of climate change on bird populations include: earlier nest initiation dates; changes in population size and distribution (predominantly northerly range extensions); shifts in the timing of migration; changes in availability of prey resources; and changes in distribution and abundance of predators (Butler and Vannesland 2000, Crick 2004, National Audubon Society 2009, NABCI 2010). The effects of climate change may severely impact wetland habitats in the arid Intermountain West. Increases in temperature without commensurate increases in precipitation will result in loss of wetland habitat, particularly seasonal and shallow wetlands used by many waterbirds as breeding, foraging, and migration stop-over sites. Wetlands that depend on snowmelt for spring recharge are particularly at risk (NABCI 2010). This is of particular concern for most wetlands in the Intermountain West which are predominantly reliant on snowmelt for source water. Significant changes in the amount of precipitation, whether increasing or decreasing, may alter salinity levels at critical sites such as Mono Lake, Great Salt Lake, and other saline water bodies in the Intermountain West. Such changes have the potential to greatly alter food resources at these sites, known to support hundreds of thousands

of waterbirds during critical life stages. Even if annual levels of precipitation remain relatively unchanged from the present, reductions in snow-pack and earlier snowmelt runoff dates can dramatically influence the timing of water availability to wetlands. The shift to earlier snowmelt dates will undoubtedly alter the wetland plant communities on which waterbirds depend. For example, earlier snow melt with reduced annual precipitation would likely diminish wetland quantity and quality in the late summer and fall, potentially leading to premature drying of important breeding and fall migration habitat. Alternatively, earlier snow melt with equivalent (or increased) annual precipitation may result in different plant communities from which waterbird migration and breeding phenologies have evolved. The indirect effects of climate change such as changes in vegetation; the spread of invasive species, increased frequency and magnitude of flood and drought events; increases in fire events; and the increased water demands from the rapidly growing human population all have the potential to negatively impact wetland and associated upland foraging habitat for waterbirds. The consequences of the effects of climate change have the potential to significantly alter the distribution, abundance, reproductive success and survival of waterbirds throughout the Intermountain West.

P h o t o b y L a r r y K r u c ke n b e r g

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POPULATION ESTIMATES & OBJECTIVES

Photo by USF WS

Waterbird population estimates in the IWWCP were generated by compiling available inventory and monitoring data from regional, statewide, and local surveys. Expert opinion and data from various sources, years, and survey techniques were collated and used to generate population estimates for 17 of the 39 waterbird species (including the CVP, LCRVP, and RMP breeding populations of Sandhill Cranes) that occur in the IWJV. The IWWCP then established spopulation objectives for these High or Moderate Concern priority waterbird species for each state and BCR. For priority migrant species, population objectives were set for individual sites that support high numbers and were derived from estimates of peak numbers of staging birds using each site. IWWCP population estimates and objectives are lacking for many waterbirds, particularly secretive marsh birds and including some priority species such as Sora and American Bittern.

waterbirds in 11 western states, including all states encompassed in the IWJV. Nearly all known and potential waterbird breeding sites within the Intermountain West were surveyed during the initial two year survey effort. Estimates generated from this inventory will represent minimum population sizes and will improve prior estimates because surveys were conducted in a more coordinated, comprehensive, and synchronized manner. Issues stemming from over-counting or undercounting due to temporal and spatial shifts in colony locations among and between years, and incomplete survey coverage should be minimal in comparison to estimates previously generated from discrete survey efforts conducted independently by many entities across many years. These results will provide the IWJV with more current and accurate information on waterbird abundance and distribution which will greatly improve our capacity for waterbird conservation planning.

In 2009â&#x20AC;&#x201C;2011 the U.S. Fish and Wildlife Service collaborated with state and NGO partners to plan and implement a comprehensive inventory of colonial 6.20

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FOCAL SPECIES

Photo by USF WS

Focal Species Approach

This list includes waterbirds that are:

Practical conservation and management considerations, along with limited data and knowledge of most waterbird populations necessitate, that only a subset of species can be used for future landscape-scale conservation planning at this time. To select focal waterbirds for this Strategy, the WST implemented a process similar to that used by California Partners in Flight for landbird conservation planning (Chase and Guepel 2005). This entailed identifying species associated with important habitat elements or microhabitat attributes, identifying species with special conservation needs, and then selecting a suite of species that together represent the full range of critical ecosystem/habitat elements within the planning area.

1. Ranked as highly imperiled or of high concern in the NAWCP;

To select focal species for IWJV habitat conservation efforts, the WST initially compiled a list of priority species from waterbird conservation plans and federal and state lists of bird conservation priorities.

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2. Ranked as high or moderate concern in the regional IWWCP; 3. Included on USFWS Birds of Conservation Concern (BCC) BCR lists (USFWS 2009); and 4. Identified as priority species in State Wildlife Action Plans (SWAPs). In total, 31 waterbird species and subspecies representing a broad array of taxonomic groups, geographic ranges, abundance, and conservation status were identified as priority species (Table 3). Most of these occur as resident or breeding birds, but migrant Common Loons, Eared Grebes, Lesser Sandhill Cranes, Franklinâ&#x20AC;&#x2122;s Gulls; and several management populations of Greater Sandhill Cranes that stage at various key locations within the IWJV are also included.

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FOCAL SPECIES Table 3 Conservation Concern Rankings for Priority Waterbirds in the Intermountain West. STATE WILDIFE ACTION PLANS Species of Greatest Conservation Concern

COMMON NAME

NAWCP 1

Common Loon Pied-billed Grebe

IWWCP 2

BCC3

AZ

High (b/m) High Concern - WH

CA

CO

X

ID X

MT

NV

X

X

X

Eared Grebe

High (m)

Western Grebe

BCR 9

X

X

High

X

X

Clark’s Grebe

High

X

American White Pelican

High (b/m)

X

Double-crested Cormorant

UT

WA

WY

X

X

X

X

X

X

X X

X

X

X

X

X

X

X

X X

X

X

X

American Bittern

High Concern - NA

High

BCR 16

Least Bittern

High Concern - WH

Moderate

BCR 33

Great Blue Heron

X

Snowy Egret

X

Cattle Egret

X

X

Black-crowned Night Heron

Moderate

White-faced Ibis

X

X

X

X

Virginia Rail

High

X BCR 9

X

X

X

X

X X

X

X

X

X

X

X X

Moderate Highest Concern - WH

Yuma Clapper Rail 6

High Concern 4

Sora

High Concern - WH

X BCR 33

X

X

X

X

X X

Moderate

SANDHILL CRANE

X

Greater Sandhill Crane

X

X

X

Central Valley Population

High (b/m)

Lower Colorado River Population

High (m); Moderate (b)

Rocky Mountain Population

High (m); Moderate (b)

Lesser Sandhill Crane

X

X

X

Moderate High Concern - NA

X

X

X Moderate

X

X

High

Green Heron

X

X

Moderate

Great Egret

5

X

X

Neotropic Cormorant

Black Rail

OR

Moderate

Red-necked Grebe

Yellow Rail 4

NM

High (m)

Franklin’s Gull

High (b/m)

California Gull

Moderate

Caspian Tern

X

X

X

X

X X

X

X

X

X

X Moderate

Black Tern

High

X

X

Least Tern (interior) Forster’s Tern

X

X

X

X

X

X

X X X

X

X

X

X

X

WH = Western Hemisphere; NA = North America; (m) = migrant; (b/m) = breeding and migrant 1. NAWCP - Colonial Waterbird Rankings are from the North American Waterbird Conservation Plan, Kushlan et al. 2002; Rankings for solitary- nesting waterbirds are from the NAWCP Update: http://www.pwrc.usgs.gov/nacwcp/pdfs/ status_assessment/FinalTableWorksheet.pdf

3. BCC - Birds of Conservation Concern, U.S. Fish and Wildlife Service Birds , 2008; Bird Conservation Region (BCR) level rankings.

2. IWWCP - Intermountain West Waterbird Conservation Plan, Ivey and Herziger 2006; all rankings are for breeding waterbirds unless otherwise noted by (m) to indicate ranking is for the migrating population or (b/m) to indicate rankings were

4. Yellow Rail - Also listed as a USFWS BCC at the FWS Regional Scale in the Pacific Region (R1), Southwest Region(R2), Mountain Prairie Region (R6), CA/NV Region (R8) and nationally.

6.22

provided for both breeding and migrant populations of a the particular species or management population.

I n t e r m o u n t a i n We s t J o i n t Ve n t u re | C o n s e r v i n g H a b i t a t T h r o u g h P a r t n e r s h i p s | w w w. i w j v. o rg


FOCAL SPECIES 5. Black Rail - species occurrence in AZ, CA, and CO are outside the IWJV boundary; Occurrences in NV are from observations in 2003 in the Virgin River and Henderson, NV areas (BCR 33; Floyd et al. 2007); Also listed as a USFWS BCC at the FWS Regional Scale in the Southwest Region(R2), Mountain Prairie Region (R6), CA/NV Region (R8) and nationally. 6. Yuma Clapper Rail - NWACP ranking is for the Yuma subspecies; confirmed breeding in Big Marsh, Clark Co , NV 2001 (Floyd et al. 2007); Also listed as a USFWS BCC at the Regional Scale in the Southwest Region (R2), Mountain Prairie Region (R6), and CA/NV Region (R8)

To facilitate selection of focal species from the list of priority waterbirds, breeding waterbirds were assigned to one or more of four wetland habitat types that are characteristic of the Intermountain West. Within each habitat type, species were then grouped into one of five nesting guilds representative of basic nest-type attributes: emergent vegetation nesters, meadows nesters, overwater floating platform nesters, tree /shrub nesters, or open ground nesters (Table 4). Migrating or wintering waterbirds were assigned to wetland habitat types and one of three foraging guilds (Table 5).

Table 4 P rimary Wetland Habitat Association and Nesting Guilds for IWJV Priority Breeding Waterbirds

WETLAND HABITAT TYPE EMERGENT WETLAND